diff --git a/R/hrg.R b/R/hrg.R
index 9fb2bc0e6f..76431457bd 100644
--- a/R/hrg.R
+++ b/R/hrg.R
@@ -287,6 +287,11 @@ hrg <- hrg_create_impl
 #' @export
 #' @cdocs igraph_from_hrg_dendrogram
 hrg_tree <- function(hrg) {
+
+  if (!inherits(hrg, "igraphHRG")) {
+    cli::cli_abort("{.arg hrg} must be an {.cls igraphHRG} object, not {.obj_type_friendly {hrg}}.")
+  }
+
   out <- from_hrg_dendrogram_impl(hrg)
 
   g <- out$graph
@@ -305,8 +310,14 @@ hrg_tree <- function(hrg) {
 #' @family hierarchical random graph functions
 #' @export
 #' @cdocs igraph_hrg_game
-sample_hrg <- hrg_game_impl
+sample_hrg <- function(hrg) {
 
+  if (!inherits(hrg, "igraphHRG")) {
+    cli::cli_abort("{.arg hrg} must be an {.cls igraphHRG} object, not {.obj_type_friendly {hrg}}.")
+  }
+
+  hrg_game_impl(hrg)
+}
 #' Predict edges based on a hierarchical random graph model
 #'
 #' `predict_edges()` uses a hierarchical random graph model to predict
diff --git a/tests/testthat/_snaps/hrg.md b/tests/testthat/_snaps/hrg.md
index 8dd969e9d2..239f540018 100644
--- a/tests/testthat/_snaps/hrg.md
+++ b/tests/testthat/_snaps/hrg.md
@@ -11,3 +11,19 @@
       method       1     -none- character
       dist.method  1     -none- character
 
+# sample_hrg() checks its argument
+
+    Code
+      sample_hrg(make_ring(10))
+    Condition
+      Error in `sample_hrg()`:
+      ! `hrg` must be an <igraphHRG> object, not an <igraph> object.
+
+# hrg_tree() checks its argument
+
+    Code
+      hrg_tree(make_ring(10))
+    Condition
+      Error in `hrg_tree()`:
+      ! `hrg` must be an <igraphHRG> object, not an <igraph> object.
+
diff --git a/tests/testthat/test-hrg.R b/tests/testthat/test-hrg.R
index c584be3d63..1262bbb77e 100644
--- a/tests/testthat/test-hrg.R
+++ b/tests/testthat/test-hrg.R
@@ -16,3 +16,16 @@ test_that("as.hclust.igraphHRG() works", {
     summary(as.hclust(hrg))
   })
 })
+
+test_that("sample_hrg() checks its argument", {
+  expect_snapshot(error = TRUE, {
+    sample_hrg(make_ring(10))
+  })
+})
+
+
+test_that("hrg_tree() checks its argument", {
+  expect_snapshot(error = TRUE, {
+    hrg_tree(make_ring(10))
+  })
+})