diff --git a/include/swift/AST/DiagnosticsSema.def b/include/swift/AST/DiagnosticsSema.def
index 6a3922506c63c..a1fceccd8f9b3 100644
--- a/include/swift/AST/DiagnosticsSema.def
+++ b/include/swift/AST/DiagnosticsSema.def
@@ -4958,6 +4958,8 @@ NOTE(iuo_to_any_coercion_note_func_result,none,
      (const ValueDecl *))
 NOTE(default_optional_to_any,none,
      "provide a default value to avoid this warning", ())
+NOTE(default_optional_parameter,none,
+     "provide a default value parameter", ())
 NOTE(force_optional_to_any,none,
      "force-unwrap the value to avoid this warning", ())
 NOTE(silence_optional_to_any,none,
diff --git a/lib/Sema/MiscDiagnostics.cpp b/lib/Sema/MiscDiagnostics.cpp
index cf7a097021ca7..a3c8c2ebca899 100644
--- a/lib/Sema/MiscDiagnostics.cpp
+++ b/lib/Sema/MiscDiagnostics.cpp
@@ -5688,6 +5688,11 @@ static void diagnoseUnintendedOptionalBehavior(const Expr *E,
           .fixItInsertAfter(arg->getEndLoc(), ")");
 
       if (kind == UnintendedInterpolationKind::Optional) {
+        // Suggest using a default interpolation value parameter.
+        Ctx.Diags.diagnose(arg->getLoc(), diag::default_optional_parameter)
+          .highlight(arg->getSourceRange())
+          .fixItInsertAfter(arg->getEndLoc(), ", default: <#default value#>");
+
         // Suggest inserting a default value.
         Ctx.Diags.diagnose(arg->getLoc(), diag::default_optional_to_any)
           .highlight(arg->getSourceRange())
diff --git a/stdlib/public/core/StringInterpolation.swift b/stdlib/public/core/StringInterpolation.swift
index e664f521e4091..ad75d37c8f13f 100644
--- a/stdlib/public/core/StringInterpolation.swift
+++ b/stdlib/public/core/StringInterpolation.swift
@@ -197,6 +197,46 @@ public struct DefaultStringInterpolation: StringInterpolationProtocol, Sendable
   }
 }
 
+extension DefaultStringInterpolation {
+  @backDeployed(before: SwiftStdlib 6.2)
+  public mutating func appendInterpolation<T>(
+    _ value: T?, 
+    default: @autoclosure () -> String
+  ) where T: TextOutputStreamable {
+    if let value {
+      self.appendInterpolation(value)
+    } else {
+      self.appendInterpolation(`default`())
+    }
+  }
+
+  @backDeployed(before: SwiftStdlib 6.2)
+  @_disfavoredOverload
+  public mutating func appendInterpolation<T>(
+    _ value: T?, 
+    default: @autoclosure () -> String
+  ) where T: CustomStringConvertible {
+    if let value {
+      self.appendInterpolation(value)
+    } else {
+      self.appendInterpolation(`default`())
+    }
+  }
+
+  @backDeployed(before: SwiftStdlib 6.2)
+  @_disfavoredOverload
+  public mutating func appendInterpolation<T>(
+    _ value: T?, 
+    default: @autoclosure () -> String
+  ) {
+    if let value {
+      self.appendInterpolation(value)
+    } else {
+      self.appendInterpolation(`default`())
+    }
+  }
+}
+
 extension DefaultStringInterpolation: CustomStringConvertible {
   @inlinable
   public var description: String {
diff --git a/test/Sema/diag_unintended_optional_behavior.swift b/test/Sema/diag_unintended_optional_behavior.swift
index 36a84226064fd..772e2ac3d0bd1 100644
--- a/test/Sema/diag_unintended_optional_behavior.swift
+++ b/test/Sema/diag_unintended_optional_behavior.swift
@@ -200,17 +200,20 @@ func warnOptionalInStringInterpolationSegment(_ o : Int?) {
   print("Always some, Always some, Always some: \(o)")
   // expected-warning@-1 {{string interpolation produces a debug description for an optional value; did you mean to make this explicit?}}
   // expected-note@-2 {{use 'String(describing:)' to silence this warning}} {{51-51=String(describing: }} {{52-52=)}} 
-  // expected-note@-3 {{provide a default value to avoid this warning}} {{52-52= ?? <#default value#>}}
+  // expected-note@-3 {{provide a default value parameter}} {{52-52=, default: <#default value#>}}
+  // expected-note@-4 {{provide a default value to avoid this warning}} {{52-52= ?? <#default value#>}}
   var i: Int? = o
   print("Always some, Always some, Always some: \(i)")
   // expected-warning@-1 {{string interpolation produces a debug description for an optional value; did you mean to make this explicit?}}
   // expected-note@-2 {{use 'String(describing:)' to silence this warning}} {{51-51=String(describing: }} {{52-52=)}}
-  // expected-note@-3 {{provide a default value to avoid this warning}} {{52-52= ?? <#default value#>}}
+  // expected-note@-3 {{provide a default value parameter}} {{52-52=, default: <#default value#>}}
+  // expected-note@-4 {{provide a default value to avoid this warning}} {{52-52= ?? <#default value#>}}
   i = nil
   print("Always some, Always some, Always some: \(o.map { $0 + 1 })")
   // expected-warning@-1 {{string interpolation produces a debug description for an optional value; did you mean to make this explicit?}}
   // expected-note@-2 {{use 'String(describing:)' to silence this warning}} {{51-51=String(describing: }} {{67-67=)}} 
-  // expected-note@-3 {{provide a default value to avoid this warning}} {{67-67= ?? <#default value#>}}
+  // expected-note@-3 {{provide a default value parameter}} {{67-67=, default: <#default value#>}}
+  // expected-note@-4 {{provide a default value to avoid this warning}} {{67-67= ?? <#default value#>}}
 
   print("Always some, Always some, Always some: \(o as Int?)") // No warning
   print("Always some, Always some, Always some: \(o.debugDescription)") // No warning.
@@ -222,7 +225,8 @@ func warnOptionalInStringInterpolationSegment(_ o : Int?) {
   print("Always some, Always some, Always some: \(ooST)")
   // expected-warning@-1 {{string interpolation produces a debug description for an optional value; did you mean to make this explicit?}}
   // expected-note@-2 {{use 'String(describing:)' to silence this warning}} {{51-51=String(describing: }} {{55-55=)}} 
-  // expected-note@-3 {{provide a default value to avoid this warning}} {{55-55= ?? <#default value#>}}  
+  // expected-note@-3 {{provide a default value parameter}} {{55-55=, default: <#default value#>}}
+  // expected-note@-4 {{provide a default value to avoid this warning}} {{55-55= ?? <#default value#>}}  
 }
 
 // Make sure we don't double diagnose
diff --git a/test/stdlib/PrintString.swift b/test/stdlib/PrintString.swift
index 45bfb946c10fd..58000c93fecd1 100644
--- a/test/stdlib/PrintString.swift
+++ b/test/stdlib/PrintString.swift
@@ -92,6 +92,11 @@ PrintTests.test("StringInterpolation") {
   
   let s2 = "aaa\(1)bbb\(2 as Any)"
   expectEqual("aaa1bbb2", s2)
+  
+  let x: Int? = 1
+  let y: Int? = nil
+  let s3 = "aaa\(x, default: "NONE")bbb\(y, default: "NONE")"
+  expectEqual("aaa1bbbNONE", s3)
 }
 
 PrintTests.test("SubstringInterpolation") {
@@ -100,6 +105,11 @@ PrintTests.test("SubstringInterpolation") {
   
   let s2 = "aaa\(1)bbb\(2 as Any)" as Substring
   expectEqual("aaa1bbb2", s2)
+  
+  let x: Int? = 1
+  let y: Int? = nil
+  let s3 = "aaa\(x, default: "NONE")bbb\(y, default: "NONE")" as Substring
+  expectEqual("aaa1bbbNONE", s3)
 }
 
 PrintTests.test("CustomStringInterpolation") {
@@ -116,6 +126,11 @@ PrintTests.test("AutoCustomStringInterpolation") {
   
   let s2 = ("aaa\(1)bbb\(2 as Any)" as MySimpleString).value
   expectEqual("aaa1bbb2", s2)
+  
+  let x: Int? = 1
+  let y: Int? = nil
+  let s3 = ("aaa\(x, default: "NONE")bbb\(y, default: "NONE")" as MySimpleString).value
+  expectEqual("aaa1bbbNONE", s3)
 }
 
 PrintTests.test("CustomStringInterpolationExtra") {