diff --git a/modules/openapi-generator/src/main/resources/r/ApiResponse.mustache b/modules/openapi-generator/src/main/resources/r/ApiResponse.mustache
index 9afb8828d555..058bdb5ca280 100644
--- a/modules/openapi-generator/src/main/resources/r/ApiResponse.mustache
+++ b/modules/openapi-generator/src/main/resources/r/ApiResponse.mustache
@@ -49,7 +49,7 @@ ApiResponse <- R6::R6Class(
     #' @param from_encoding The encoding of the raw response.
     #' @param to_encoding The target encoding of the return value.
     #' @export
-    response_as_text = function(from_encoding = NULL, to_encoding = "UTF-8") {
+    response_as_text = function(from_encoding = "", to_encoding = "UTF-8") {
       text_response <- iconv(readBin(self$response, character()), from = from_encoding, to = to_encoding)
       if (is.na(text_response)) {
         warning("The response is binary and will not be converted to text.")
diff --git a/modules/openapi-generator/src/main/resources/r/libraries/httr2/api_client.mustache b/modules/openapi-generator/src/main/resources/r/libraries/httr2/api_client.mustache
index 54148bca6533..e888008f4597 100644
--- a/modules/openapi-generator/src/main/resources/r/libraries/httr2/api_client.mustache
+++ b/modules/openapi-generator/src/main/resources/r/libraries/httr2/api_client.mustache
@@ -323,7 +323,11 @@ ApiClient  <- R6::R6Class(
         api_response <- ApiResponse$new()
         api_response$status_code <- resp %>% resp_status()
         api_response$status_code_desc <- resp %>% resp_status_desc()
-        api_response$response <- resp %>% resp_body_raw()
+        if (length(resp$body) == 0) {
+          api_response$response <- NULL
+        } else {
+          api_response$response <- resp %>% resp_body_raw()
+        }
         api_response$headers <- resp %>% resp_headers()
 
         api_response
diff --git a/modules/openapi-generator/src/main/resources/r/modelGeneric.mustache b/modules/openapi-generator/src/main/resources/r/modelGeneric.mustache
index f967537e2944..cdafe398e0d8 100644
--- a/modules/openapi-generator/src/main/resources/r/modelGeneric.mustache
+++ b/modules/openapi-generator/src/main/resources/r/modelGeneric.mustache
@@ -330,7 +330,7 @@
           {{/isArray}}
           {{#isMap}}
           {{#isPrimitiveType}}
-            {{#isNumeric}}%d{{/isNumeric}}{{^isNumeric}}{{^isBoolean}}"{{/isBoolean}}%s{{^isBoolean}}"{{/isBoolean}}{{/isNumeric}}
+            {{#isNumeric}}%d{{/isNumeric}}{{^isNumeric}}{{^isBoolean}}{{/isBoolean}}%s{{^isBoolean}}{{/isBoolean}}{{/isNumeric}}
           {{/isPrimitiveType}}
           {{^isPrimitiveType}}%s
           {{/isPrimitiveType}}
diff --git a/modules/openapi-generator/src/test/resources/3_0/r/petstore.yaml b/modules/openapi-generator/src/test/resources/3_0/r/petstore.yaml
index 2fd09bffbf84..70497d526ed5 100644
--- a/modules/openapi-generator/src/test/resources/3_0/r/petstore.yaml
+++ b/modules/openapi-generator/src/test/resources/3_0/r/petstore.yaml
@@ -958,6 +958,15 @@ components:
             - sold
       xml:
         name: Pet
+    PetMap:
+      title: a PetMap
+      description: A mock map of a pet and some properties
+      type: object
+      properties:
+        pet:
+          type: object
+          additionalProperties:
+            type: string
     ApiResponse:
       title: An uploaded response
       description: Describes the result of uploading an image resource
diff --git a/samples/client/echo_api/r/R/api_response.R b/samples/client/echo_api/r/R/api_response.R
index c98bb5122750..404f2ec8a9e8 100644
--- a/samples/client/echo_api/r/R/api_response.R
+++ b/samples/client/echo_api/r/R/api_response.R
@@ -56,7 +56,7 @@ ApiResponse <- R6::R6Class(
     #' @param from_encoding The encoding of the raw response.
     #' @param to_encoding The target encoding of the return value.
     #' @export
-    response_as_text = function(from_encoding = NULL, to_encoding = "UTF-8") {
+    response_as_text = function(from_encoding = "", to_encoding = "UTF-8") {
       text_response <- iconv(readBin(self$response, character()), from = from_encoding, to = to_encoding)
       if (is.na(text_response)) {
         warning("The response is binary and will not be converted to text.")
diff --git a/samples/client/petstore/R-httr2-wrapper/.openapi-generator/FILES b/samples/client/petstore/R-httr2-wrapper/.openapi-generator/FILES
index 5023966da14b..379998b2a2b8 100644
--- a/samples/client/petstore/R-httr2-wrapper/.openapi-generator/FILES
+++ b/samples/client/petstore/R-httr2-wrapper/.openapi-generator/FILES
@@ -28,6 +28,7 @@ R/one_of_primitive_type_test.R
 R/order.R
 R/pet.R
 R/pet_api.R
+R/pet_map.R
 R/petstore_api.R
 R/pig.R
 R/special.R
@@ -59,6 +60,7 @@ docs/OneOfPrimitiveTypeTest.md
 docs/Order.md
 docs/Pet.md
 docs/PetApi.md
+docs/PetMap.md
 docs/Pig.md
 docs/Special.md
 docs/StoreApi.md
diff --git a/samples/client/petstore/R-httr2-wrapper/NAMESPACE b/samples/client/petstore/R-httr2-wrapper/NAMESPACE
index fd062786db13..fd66fd4ef7e8 100644
--- a/samples/client/petstore/R-httr2-wrapper/NAMESPACE
+++ b/samples/client/petstore/R-httr2-wrapper/NAMESPACE
@@ -34,6 +34,7 @@ export(NestedOneOf)
 export(OneOfPrimitiveTypeTest)
 export(Order)
 export(Pet)
+export(PetMap)
 export(Pig)
 export(Special)
 export(Tag)
diff --git a/samples/client/petstore/R-httr2-wrapper/R/api_client.R b/samples/client/petstore/R-httr2-wrapper/R/api_client.R
index 5e51a57b302b..32aa262f5545 100644
--- a/samples/client/petstore/R-httr2-wrapper/R/api_client.R
+++ b/samples/client/petstore/R-httr2-wrapper/R/api_client.R
@@ -312,7 +312,11 @@ ApiClient  <- R6::R6Class(
         api_response <- ApiResponse$new()
         api_response$status_code <- resp %>% resp_status()
         api_response$status_code_desc <- resp %>% resp_status_desc()
-        api_response$response <- resp %>% resp_body_raw()
+        if (length(resp$body) == 0) {
+          api_response$response <- NULL
+        } else {
+          api_response$response <- resp %>% resp_body_raw()
+        }
         api_response$headers <- resp %>% resp_headers()
 
         api_response
diff --git a/samples/client/petstore/R-httr2-wrapper/R/api_response.R b/samples/client/petstore/R-httr2-wrapper/R/api_response.R
index f76d20d3f769..b84d66f6ee0f 100644
--- a/samples/client/petstore/R-httr2-wrapper/R/api_response.R
+++ b/samples/client/petstore/R-httr2-wrapper/R/api_response.R
@@ -55,7 +55,7 @@ ApiResponse <- R6::R6Class(
     #' @param from_encoding The encoding of the raw response.
     #' @param to_encoding The target encoding of the return value.
     #' @export
-    response_as_text = function(from_encoding = NULL, to_encoding = "UTF-8") {
+    response_as_text = function(from_encoding = "", to_encoding = "UTF-8") {
       text_response <- iconv(readBin(self$response, character()), from = from_encoding, to = to_encoding)
       if (is.na(text_response)) {
         warning("The response is binary and will not be converted to text.")
diff --git a/samples/client/petstore/R-httr2-wrapper/R/pet_map.R b/samples/client/petstore/R-httr2-wrapper/R/pet_map.R
new file mode 100644
index 000000000000..80d9eb3abf89
--- /dev/null
+++ b/samples/client/petstore/R-httr2-wrapper/R/pet_map.R
@@ -0,0 +1,195 @@
+#' Create a new PetMap
+#'
+#' @description
+#' A mock map of a pet and some properties
+#'
+#' @docType class
+#' @title PetMap
+#' @description PetMap Class
+#' @format An \code{R6Class} generator object
+#' @field pet  named list(character) [optional]
+#' @field _field_list a list of fields list(character)
+#' @field additional_properties additional properties list(character) [optional]
+#' @importFrom R6 R6Class
+#' @importFrom jsonlite fromJSON toJSON
+#' @export
+PetMap <- R6::R6Class(
+  "PetMap",
+  public = list(
+    `pet` = NULL,
+    `_field_list` = c("pet"),
+    `additional_properties` = list(),
+    #' Initialize a new PetMap class.
+    #'
+    #' @description
+    #' Initialize a new PetMap class.
+    #'
+    #' @param pet pet
+    #' @param additional_properties additional properties (optional)
+    #' @param ... Other optional arguments.
+    #' @export
+    initialize = function(`pet` = NULL, additional_properties = NULL, ...) {
+      if (!is.null(`pet`)) {
+        stopifnot(is.vector(`pet`), length(`pet`) != 0)
+        sapply(`pet`, function(x) stopifnot(is.character(x)))
+        self$`pet` <- `pet`
+      }
+      if (!is.null(additional_properties)) {
+        for (key in names(additional_properties)) {
+          self$additional_properties[[key]] <- additional_properties[[key]]
+        }
+      }
+    },
+    #' To JSON string
+    #'
+    #' @description
+    #' To JSON String
+    #'
+    #' @return PetMap in JSON format
+    #' @export
+    toJSON = function() {
+      PetMapObject <- list()
+      if (!is.null(self$`pet`)) {
+        PetMapObject[["pet"]] <-
+          self$`pet`
+      }
+      for (key in names(self$additional_properties)) {
+        PetMapObject[[key]] <- self$additional_properties[[key]]
+      }
+
+      PetMapObject
+    },
+    #' Deserialize JSON string into an instance of PetMap
+    #'
+    #' @description
+    #' Deserialize JSON string into an instance of PetMap
+    #'
+    #' @param input_json the JSON input
+    #' @return the instance of PetMap
+    #' @export
+    fromJSON = function(input_json) {
+      this_object <- jsonlite::fromJSON(input_json)
+      if (!is.null(this_object$`pet`)) {
+        self$`pet` <- ApiClient$new()$deserializeObj(this_object$`pet`, "map(character)", loadNamespace("petstore"))
+      }
+      # process additional properties/fields in the payload
+      for (key in names(this_object)) {
+        if (!(key %in% self$`_field_list`)) { # json key not in list of fields
+          self$additional_properties[[key]] <- this_object[[key]]
+        }
+      }
+
+      self
+    },
+    #' To JSON string
+    #'
+    #' @description
+    #' To JSON String
+    #'
+    #' @return PetMap in JSON format
+    #' @export
+    toJSONString = function() {
+      jsoncontent <- c(
+        if (!is.null(self$`pet`)) {
+          sprintf(
+          '"pet":
+            %s
+          ',
+          jsonlite::toJSON(lapply(self$`pet`, function(x){ x }), auto_unbox = TRUE, digits = NA)
+          )
+        }
+      )
+      jsoncontent <- paste(jsoncontent, collapse = ",")
+      json_string <- as.character(jsonlite::minify(paste("{", jsoncontent, "}", sep = "")))
+      json_obj <- jsonlite::fromJSON(json_string)
+      for (key in names(self$additional_properties)) {
+        json_obj[[key]] <- self$additional_properties[[key]]
+      }
+      json_string <- as.character(jsonlite::minify(jsonlite::toJSON(json_obj, auto_unbox = TRUE, digits = NA)))
+    },
+    #' Deserialize JSON string into an instance of PetMap
+    #'
+    #' @description
+    #' Deserialize JSON string into an instance of PetMap
+    #'
+    #' @param input_json the JSON input
+    #' @return the instance of PetMap
+    #' @export
+    fromJSONString = function(input_json) {
+      this_object <- jsonlite::fromJSON(input_json)
+      self$`pet` <- ApiClient$new()$deserializeObj(this_object$`pet`, "map(character)", loadNamespace("petstore"))
+      # process additional properties/fields in the payload
+      for (key in names(this_object)) {
+        if (!(key %in% self$`_field_list`)) { # json key not in list of fields
+          self$additional_properties[[key]] <- this_object[[key]]
+        }
+      }
+
+      self
+    },
+    #' Validate JSON input with respect to PetMap
+    #'
+    #' @description
+    #' Validate JSON input with respect to PetMap and throw an exception if invalid
+    #'
+    #' @param input the JSON input
+    #' @export
+    validateJSON = function(input) {
+      input_json <- jsonlite::fromJSON(input)
+    },
+    #' To string (JSON format)
+    #'
+    #' @description
+    #' To string (JSON format)
+    #'
+    #' @return String representation of PetMap
+    #' @export
+    toString = function() {
+      self$toJSONString()
+    },
+    #' Return true if the values in all fields are valid.
+    #'
+    #' @description
+    #' Return true if the values in all fields are valid.
+    #'
+    #' @return true if the values in all fields are valid.
+    #' @export
+    isValid = function() {
+      TRUE
+    },
+    #' Return a list of invalid fields (if any).
+    #'
+    #' @description
+    #' Return a list of invalid fields (if any).
+    #'
+    #' @return A list of invalid fields (if any).
+    #' @export
+    getInvalidFields = function() {
+      invalid_fields <- list()
+      invalid_fields
+    },
+    #' Print the object
+    #'
+    #' @description
+    #' Print the object
+    #'
+    #' @export
+    print = function() {
+      print(jsonlite::prettify(self$toJSONString()))
+      invisible(self)
+    }
+  ),
+  # Lock the class to prevent modifications to the method or field
+  lock_class = TRUE
+)
+## Uncomment below to unlock the class to allow modifications of the method or field
+# PetMap$unlock()
+#
+## Below is an example to define the print function
+# PetMap$set("public", "print", function(...) {
+#   print(jsonlite::prettify(self$toJSONString()))
+#   invisible(self)
+# })
+## Uncomment below to lock the class to prevent modifications to the method or field
+# PetMap$lock()
+
diff --git a/samples/client/petstore/R-httr2-wrapper/README.md b/samples/client/petstore/R-httr2-wrapper/README.md
index 888ff773a75f..0f142b8291bd 100644
--- a/samples/client/petstore/R-httr2-wrapper/README.md
+++ b/samples/client/petstore/R-httr2-wrapper/README.md
@@ -122,6 +122,7 @@ Class | Method | HTTP request | Description
  - [OneOfPrimitiveTypeTest](docs/OneOfPrimitiveTypeTest.md)
  - [Order](docs/Order.md)
  - [Pet](docs/Pet.md)
+ - [PetMap](docs/PetMap.md)
  - [Pig](docs/Pig.md)
  - [Special](docs/Special.md)
  - [Tag](docs/Tag.md)
diff --git a/samples/client/petstore/R-httr2-wrapper/docs/PetMap.md b/samples/client/petstore/R-httr2-wrapper/docs/PetMap.md
new file mode 100644
index 000000000000..ba53785e1167
--- /dev/null
+++ b/samples/client/petstore/R-httr2-wrapper/docs/PetMap.md
@@ -0,0 +1,10 @@
+# petstore::PetMap
+
+A mock map of a pet and some properties
+
+## Properties
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**pet** | **map(character)** |  | [optional] 
+
+
diff --git a/samples/client/petstore/R-httr2-wrapper/tests/testthat/test_pet_map.R b/samples/client/petstore/R-httr2-wrapper/tests/testthat/test_pet_map.R
new file mode 100644
index 000000000000..e5ee9ecf9df6
--- /dev/null
+++ b/samples/client/petstore/R-httr2-wrapper/tests/testthat/test_pet_map.R
@@ -0,0 +1,13 @@
+# Automatically generated by openapi-generator (https://openapi-generator.tech)
+# Please update as you see appropriate
+
+context("Test PetMap")
+
+model_instance <- PetMap$new()
+
+test_that("pet", {
+  # tests for the property `pet` (map(character))
+
+  # uncomment below to test the property
+  #expect_equal(model.instance$`pet`, "EXPECTED_RESULT")
+})
diff --git a/samples/client/petstore/R-httr2/.openapi-generator/FILES b/samples/client/petstore/R-httr2/.openapi-generator/FILES
index e3ca4f60cbc2..07243c898d78 100644
--- a/samples/client/petstore/R-httr2/.openapi-generator/FILES
+++ b/samples/client/petstore/R-httr2/.openapi-generator/FILES
@@ -28,6 +28,7 @@ R/one_of_primitive_type_test.R
 R/order.R
 R/pet.R
 R/pet_api.R
+R/pet_map.R
 R/pig.R
 R/special.R
 R/store_api.R
@@ -58,6 +59,7 @@ docs/OneOfPrimitiveTypeTest.md
 docs/Order.md
 docs/Pet.md
 docs/PetApi.md
+docs/PetMap.md
 docs/Pig.md
 docs/Special.md
 docs/StoreApi.md
diff --git a/samples/client/petstore/R-httr2/NAMESPACE b/samples/client/petstore/R-httr2/NAMESPACE
index e196ce103b39..29a7f89e22fd 100644
--- a/samples/client/petstore/R-httr2/NAMESPACE
+++ b/samples/client/petstore/R-httr2/NAMESPACE
@@ -32,6 +32,7 @@ export(NestedOneOf)
 export(OneOfPrimitiveTypeTest)
 export(Order)
 export(Pet)
+export(PetMap)
 export(Pig)
 export(Special)
 export(Tag)
diff --git a/samples/client/petstore/R-httr2/R/api_client.R b/samples/client/petstore/R-httr2/R/api_client.R
index 5e51a57b302b..32aa262f5545 100644
--- a/samples/client/petstore/R-httr2/R/api_client.R
+++ b/samples/client/petstore/R-httr2/R/api_client.R
@@ -312,7 +312,11 @@ ApiClient  <- R6::R6Class(
         api_response <- ApiResponse$new()
         api_response$status_code <- resp %>% resp_status()
         api_response$status_code_desc <- resp %>% resp_status_desc()
-        api_response$response <- resp %>% resp_body_raw()
+        if (length(resp$body) == 0) {
+          api_response$response <- NULL
+        } else {
+          api_response$response <- resp %>% resp_body_raw()
+        }
         api_response$headers <- resp %>% resp_headers()
 
         api_response
diff --git a/samples/client/petstore/R-httr2/R/api_response.R b/samples/client/petstore/R-httr2/R/api_response.R
index f76d20d3f769..b84d66f6ee0f 100644
--- a/samples/client/petstore/R-httr2/R/api_response.R
+++ b/samples/client/petstore/R-httr2/R/api_response.R
@@ -55,7 +55,7 @@ ApiResponse <- R6::R6Class(
     #' @param from_encoding The encoding of the raw response.
     #' @param to_encoding The target encoding of the return value.
     #' @export
-    response_as_text = function(from_encoding = NULL, to_encoding = "UTF-8") {
+    response_as_text = function(from_encoding = "", to_encoding = "UTF-8") {
       text_response <- iconv(readBin(self$response, character()), from = from_encoding, to = to_encoding)
       if (is.na(text_response)) {
         warning("The response is binary and will not be converted to text.")
diff --git a/samples/client/petstore/R-httr2/R/pet_map.R b/samples/client/petstore/R-httr2/R/pet_map.R
new file mode 100644
index 000000000000..5fe81b5dd05e
--- /dev/null
+++ b/samples/client/petstore/R-httr2/R/pet_map.R
@@ -0,0 +1,162 @@
+#' Create a new PetMap
+#'
+#' @description
+#' A mock map of a pet and some properties
+#'
+#' @docType class
+#' @title PetMap
+#' @description PetMap Class
+#' @format An \code{R6Class} generator object
+#' @field pet  named list(character) [optional]
+#' @importFrom R6 R6Class
+#' @importFrom jsonlite fromJSON toJSON
+#' @export
+PetMap <- R6::R6Class(
+  "PetMap",
+  public = list(
+    `pet` = NULL,
+    #' Initialize a new PetMap class.
+    #'
+    #' @description
+    #' Initialize a new PetMap class.
+    #'
+    #' @param pet pet
+    #' @param ... Other optional arguments.
+    #' @export
+    initialize = function(`pet` = NULL, ...) {
+      if (!is.null(`pet`)) {
+        stopifnot(is.vector(`pet`), length(`pet`) != 0)
+        sapply(`pet`, function(x) stopifnot(is.character(x)))
+        self$`pet` <- `pet`
+      }
+    },
+    #' To JSON string
+    #'
+    #' @description
+    #' To JSON String
+    #'
+    #' @return PetMap in JSON format
+    #' @export
+    toJSON = function() {
+      PetMapObject <- list()
+      if (!is.null(self$`pet`)) {
+        PetMapObject[["pet"]] <-
+          self$`pet`
+      }
+      PetMapObject
+    },
+    #' Deserialize JSON string into an instance of PetMap
+    #'
+    #' @description
+    #' Deserialize JSON string into an instance of PetMap
+    #'
+    #' @param input_json the JSON input
+    #' @return the instance of PetMap
+    #' @export
+    fromJSON = function(input_json) {
+      this_object <- jsonlite::fromJSON(input_json)
+      if (!is.null(this_object$`pet`)) {
+        self$`pet` <- ApiClient$new()$deserializeObj(this_object$`pet`, "map(character)", loadNamespace("petstore"))
+      }
+      self
+    },
+    #' To JSON string
+    #'
+    #' @description
+    #' To JSON String
+    #'
+    #' @return PetMap in JSON format
+    #' @export
+    toJSONString = function() {
+      jsoncontent <- c(
+        if (!is.null(self$`pet`)) {
+          sprintf(
+          '"pet":
+            %s
+          ',
+          jsonlite::toJSON(lapply(self$`pet`, function(x){ x }), auto_unbox = TRUE, digits = NA)
+          )
+        }
+      )
+      jsoncontent <- paste(jsoncontent, collapse = ",")
+      json_string <- as.character(jsonlite::minify(paste("{", jsoncontent, "}", sep = "")))
+    },
+    #' Deserialize JSON string into an instance of PetMap
+    #'
+    #' @description
+    #' Deserialize JSON string into an instance of PetMap
+    #'
+    #' @param input_json the JSON input
+    #' @return the instance of PetMap
+    #' @export
+    fromJSONString = function(input_json) {
+      this_object <- jsonlite::fromJSON(input_json)
+      self$`pet` <- ApiClient$new()$deserializeObj(this_object$`pet`, "map(character)", loadNamespace("petstore"))
+      self
+    },
+    #' Validate JSON input with respect to PetMap
+    #'
+    #' @description
+    #' Validate JSON input with respect to PetMap and throw an exception if invalid
+    #'
+    #' @param input the JSON input
+    #' @export
+    validateJSON = function(input) {
+      input_json <- jsonlite::fromJSON(input)
+    },
+    #' To string (JSON format)
+    #'
+    #' @description
+    #' To string (JSON format)
+    #'
+    #' @return String representation of PetMap
+    #' @export
+    toString = function() {
+      self$toJSONString()
+    },
+    #' Return true if the values in all fields are valid.
+    #'
+    #' @description
+    #' Return true if the values in all fields are valid.
+    #'
+    #' @return true if the values in all fields are valid.
+    #' @export
+    isValid = function() {
+      TRUE
+    },
+    #' Return a list of invalid fields (if any).
+    #'
+    #' @description
+    #' Return a list of invalid fields (if any).
+    #'
+    #' @return A list of invalid fields (if any).
+    #' @export
+    getInvalidFields = function() {
+      invalid_fields <- list()
+      invalid_fields
+    },
+    #' Print the object
+    #'
+    #' @description
+    #' Print the object
+    #'
+    #' @export
+    print = function() {
+      print(jsonlite::prettify(self$toJSONString()))
+      invisible(self)
+    }
+  ),
+  # Lock the class to prevent modifications to the method or field
+  lock_class = TRUE
+)
+## Uncomment below to unlock the class to allow modifications of the method or field
+# PetMap$unlock()
+#
+## Below is an example to define the print function
+# PetMap$set("public", "print", function(...) {
+#   print(jsonlite::prettify(self$toJSONString()))
+#   invisible(self)
+# })
+## Uncomment below to lock the class to prevent modifications to the method or field
+# PetMap$lock()
+
diff --git a/samples/client/petstore/R-httr2/README.md b/samples/client/petstore/R-httr2/README.md
index 47e4370616c9..d2107f853f6b 100644
--- a/samples/client/petstore/R-httr2/README.md
+++ b/samples/client/petstore/R-httr2/README.md
@@ -122,6 +122,7 @@ Class | Method | HTTP request | Description
  - [OneOfPrimitiveTypeTest](docs/OneOfPrimitiveTypeTest.md)
  - [Order](docs/Order.md)
  - [Pet](docs/Pet.md)
+ - [PetMap](docs/PetMap.md)
  - [Pig](docs/Pig.md)
  - [Special](docs/Special.md)
  - [Tag](docs/Tag.md)
diff --git a/samples/client/petstore/R-httr2/docs/PetMap.md b/samples/client/petstore/R-httr2/docs/PetMap.md
new file mode 100644
index 000000000000..ba53785e1167
--- /dev/null
+++ b/samples/client/petstore/R-httr2/docs/PetMap.md
@@ -0,0 +1,10 @@
+# petstore::PetMap
+
+A mock map of a pet and some properties
+
+## Properties
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**pet** | **map(character)** |  | [optional] 
+
+
diff --git a/samples/client/petstore/R-httr2/tests/testthat/test_pet_map.R b/samples/client/petstore/R-httr2/tests/testthat/test_pet_map.R
new file mode 100644
index 000000000000..e5ee9ecf9df6
--- /dev/null
+++ b/samples/client/petstore/R-httr2/tests/testthat/test_pet_map.R
@@ -0,0 +1,13 @@
+# Automatically generated by openapi-generator (https://openapi-generator.tech)
+# Please update as you see appropriate
+
+context("Test PetMap")
+
+model_instance <- PetMap$new()
+
+test_that("pet", {
+  # tests for the property `pet` (map(character))
+
+  # uncomment below to test the property
+  #expect_equal(model.instance$`pet`, "EXPECTED_RESULT")
+})
diff --git a/samples/client/petstore/R/.openapi-generator/FILES b/samples/client/petstore/R/.openapi-generator/FILES
index 9a7a9f21724e..43681d7ddb2c 100644
--- a/samples/client/petstore/R/.openapi-generator/FILES
+++ b/samples/client/petstore/R/.openapi-generator/FILES
@@ -28,6 +28,7 @@ R/one_of_primitive_type_test.R
 R/order.R
 R/pet.R
 R/pet_api.R
+R/pet_map.R
 R/pig.R
 R/special.R
 R/store_api.R
@@ -58,6 +59,7 @@ docs/OneOfPrimitiveTypeTest.md
 docs/Order.md
 docs/Pet.md
 docs/PetApi.md
+docs/PetMap.md
 docs/Pig.md
 docs/Special.md
 docs/StoreApi.md
diff --git a/samples/client/petstore/R/NAMESPACE b/samples/client/petstore/R/NAMESPACE
index afcc404eca78..0b48a9205360 100644
--- a/samples/client/petstore/R/NAMESPACE
+++ b/samples/client/petstore/R/NAMESPACE
@@ -32,6 +32,7 @@ export(NestedOneOf)
 export(OneOfPrimitiveTypeTest)
 export(Order)
 export(Pet)
+export(PetMap)
 export(Pig)
 export(Special)
 export(Tag)
diff --git a/samples/client/petstore/R/R/api_response.R b/samples/client/petstore/R/R/api_response.R
index f76d20d3f769..b84d66f6ee0f 100644
--- a/samples/client/petstore/R/R/api_response.R
+++ b/samples/client/petstore/R/R/api_response.R
@@ -55,7 +55,7 @@ ApiResponse <- R6::R6Class(
     #' @param from_encoding The encoding of the raw response.
     #' @param to_encoding The target encoding of the return value.
     #' @export
-    response_as_text = function(from_encoding = NULL, to_encoding = "UTF-8") {
+    response_as_text = function(from_encoding = "", to_encoding = "UTF-8") {
       text_response <- iconv(readBin(self$response, character()), from = from_encoding, to = to_encoding)
       if (is.na(text_response)) {
         warning("The response is binary and will not be converted to text.")
diff --git a/samples/client/petstore/R/R/pet_map.R b/samples/client/petstore/R/R/pet_map.R
new file mode 100644
index 000000000000..80d9eb3abf89
--- /dev/null
+++ b/samples/client/petstore/R/R/pet_map.R
@@ -0,0 +1,195 @@
+#' Create a new PetMap
+#'
+#' @description
+#' A mock map of a pet and some properties
+#'
+#' @docType class
+#' @title PetMap
+#' @description PetMap Class
+#' @format An \code{R6Class} generator object
+#' @field pet  named list(character) [optional]
+#' @field _field_list a list of fields list(character)
+#' @field additional_properties additional properties list(character) [optional]
+#' @importFrom R6 R6Class
+#' @importFrom jsonlite fromJSON toJSON
+#' @export
+PetMap <- R6::R6Class(
+  "PetMap",
+  public = list(
+    `pet` = NULL,
+    `_field_list` = c("pet"),
+    `additional_properties` = list(),
+    #' Initialize a new PetMap class.
+    #'
+    #' @description
+    #' Initialize a new PetMap class.
+    #'
+    #' @param pet pet
+    #' @param additional_properties additional properties (optional)
+    #' @param ... Other optional arguments.
+    #' @export
+    initialize = function(`pet` = NULL, additional_properties = NULL, ...) {
+      if (!is.null(`pet`)) {
+        stopifnot(is.vector(`pet`), length(`pet`) != 0)
+        sapply(`pet`, function(x) stopifnot(is.character(x)))
+        self$`pet` <- `pet`
+      }
+      if (!is.null(additional_properties)) {
+        for (key in names(additional_properties)) {
+          self$additional_properties[[key]] <- additional_properties[[key]]
+        }
+      }
+    },
+    #' To JSON string
+    #'
+    #' @description
+    #' To JSON String
+    #'
+    #' @return PetMap in JSON format
+    #' @export
+    toJSON = function() {
+      PetMapObject <- list()
+      if (!is.null(self$`pet`)) {
+        PetMapObject[["pet"]] <-
+          self$`pet`
+      }
+      for (key in names(self$additional_properties)) {
+        PetMapObject[[key]] <- self$additional_properties[[key]]
+      }
+
+      PetMapObject
+    },
+    #' Deserialize JSON string into an instance of PetMap
+    #'
+    #' @description
+    #' Deserialize JSON string into an instance of PetMap
+    #'
+    #' @param input_json the JSON input
+    #' @return the instance of PetMap
+    #' @export
+    fromJSON = function(input_json) {
+      this_object <- jsonlite::fromJSON(input_json)
+      if (!is.null(this_object$`pet`)) {
+        self$`pet` <- ApiClient$new()$deserializeObj(this_object$`pet`, "map(character)", loadNamespace("petstore"))
+      }
+      # process additional properties/fields in the payload
+      for (key in names(this_object)) {
+        if (!(key %in% self$`_field_list`)) { # json key not in list of fields
+          self$additional_properties[[key]] <- this_object[[key]]
+        }
+      }
+
+      self
+    },
+    #' To JSON string
+    #'
+    #' @description
+    #' To JSON String
+    #'
+    #' @return PetMap in JSON format
+    #' @export
+    toJSONString = function() {
+      jsoncontent <- c(
+        if (!is.null(self$`pet`)) {
+          sprintf(
+          '"pet":
+            %s
+          ',
+          jsonlite::toJSON(lapply(self$`pet`, function(x){ x }), auto_unbox = TRUE, digits = NA)
+          )
+        }
+      )
+      jsoncontent <- paste(jsoncontent, collapse = ",")
+      json_string <- as.character(jsonlite::minify(paste("{", jsoncontent, "}", sep = "")))
+      json_obj <- jsonlite::fromJSON(json_string)
+      for (key in names(self$additional_properties)) {
+        json_obj[[key]] <- self$additional_properties[[key]]
+      }
+      json_string <- as.character(jsonlite::minify(jsonlite::toJSON(json_obj, auto_unbox = TRUE, digits = NA)))
+    },
+    #' Deserialize JSON string into an instance of PetMap
+    #'
+    #' @description
+    #' Deserialize JSON string into an instance of PetMap
+    #'
+    #' @param input_json the JSON input
+    #' @return the instance of PetMap
+    #' @export
+    fromJSONString = function(input_json) {
+      this_object <- jsonlite::fromJSON(input_json)
+      self$`pet` <- ApiClient$new()$deserializeObj(this_object$`pet`, "map(character)", loadNamespace("petstore"))
+      # process additional properties/fields in the payload
+      for (key in names(this_object)) {
+        if (!(key %in% self$`_field_list`)) { # json key not in list of fields
+          self$additional_properties[[key]] <- this_object[[key]]
+        }
+      }
+
+      self
+    },
+    #' Validate JSON input with respect to PetMap
+    #'
+    #' @description
+    #' Validate JSON input with respect to PetMap and throw an exception if invalid
+    #'
+    #' @param input the JSON input
+    #' @export
+    validateJSON = function(input) {
+      input_json <- jsonlite::fromJSON(input)
+    },
+    #' To string (JSON format)
+    #'
+    #' @description
+    #' To string (JSON format)
+    #'
+    #' @return String representation of PetMap
+    #' @export
+    toString = function() {
+      self$toJSONString()
+    },
+    #' Return true if the values in all fields are valid.
+    #'
+    #' @description
+    #' Return true if the values in all fields are valid.
+    #'
+    #' @return true if the values in all fields are valid.
+    #' @export
+    isValid = function() {
+      TRUE
+    },
+    #' Return a list of invalid fields (if any).
+    #'
+    #' @description
+    #' Return a list of invalid fields (if any).
+    #'
+    #' @return A list of invalid fields (if any).
+    #' @export
+    getInvalidFields = function() {
+      invalid_fields <- list()
+      invalid_fields
+    },
+    #' Print the object
+    #'
+    #' @description
+    #' Print the object
+    #'
+    #' @export
+    print = function() {
+      print(jsonlite::prettify(self$toJSONString()))
+      invisible(self)
+    }
+  ),
+  # Lock the class to prevent modifications to the method or field
+  lock_class = TRUE
+)
+## Uncomment below to unlock the class to allow modifications of the method or field
+# PetMap$unlock()
+#
+## Below is an example to define the print function
+# PetMap$set("public", "print", function(...) {
+#   print(jsonlite::prettify(self$toJSONString()))
+#   invisible(self)
+# })
+## Uncomment below to lock the class to prevent modifications to the method or field
+# PetMap$lock()
+
diff --git a/samples/client/petstore/R/README.md b/samples/client/petstore/R/README.md
index 3ccba825c793..04327fa38766 100644
--- a/samples/client/petstore/R/README.md
+++ b/samples/client/petstore/R/README.md
@@ -122,6 +122,7 @@ Class | Method | HTTP request | Description
  - [OneOfPrimitiveTypeTest](docs/OneOfPrimitiveTypeTest.md)
  - [Order](docs/Order.md)
  - [Pet](docs/Pet.md)
+ - [PetMap](docs/PetMap.md)
  - [Pig](docs/Pig.md)
  - [Special](docs/Special.md)
  - [Tag](docs/Tag.md)
diff --git a/samples/client/petstore/R/docs/PetMap.md b/samples/client/petstore/R/docs/PetMap.md
new file mode 100644
index 000000000000..ba53785e1167
--- /dev/null
+++ b/samples/client/petstore/R/docs/PetMap.md
@@ -0,0 +1,10 @@
+# petstore::PetMap
+
+A mock map of a pet and some properties
+
+## Properties
+Name | Type | Description | Notes
+------------ | ------------- | ------------- | -------------
+**pet** | **map(character)** |  | [optional] 
+
+
diff --git a/samples/client/petstore/R/tests/testthat/test_pet_map.R b/samples/client/petstore/R/tests/testthat/test_pet_map.R
new file mode 100644
index 000000000000..e5ee9ecf9df6
--- /dev/null
+++ b/samples/client/petstore/R/tests/testthat/test_pet_map.R
@@ -0,0 +1,13 @@
+# Automatically generated by openapi-generator (https://openapi-generator.tech)
+# Please update as you see appropriate
+
+context("Test PetMap")
+
+model_instance <- PetMap$new()
+
+test_that("pet", {
+  # tests for the property `pet` (map(character))
+
+  # uncomment below to test the property
+  #expect_equal(model.instance$`pet`, "EXPECTED_RESULT")
+})