diff --git a/lib/AST/Decl.cpp b/lib/AST/Decl.cpp
index 13a4d46dcac9e..29d993b205027 100644
--- a/lib/AST/Decl.cpp
+++ b/lib/AST/Decl.cpp
@@ -6106,8 +6106,8 @@ ParamDecl::ParamDecl(SourceLoc specifierLoc,
 
 ParamDecl *ParamDecl::cloneWithoutType(const ASTContext &Ctx, ParamDecl *PD) {
   auto *Clone = new (Ctx) ParamDecl(
-      PD->getSpecifierLoc(), PD->getArgumentNameLoc(), PD->getArgumentName(),
-      PD->getArgumentNameLoc(), PD->getParameterName(), PD->getDeclContext());
+      SourceLoc(), SourceLoc(), PD->getArgumentName(),
+      SourceLoc(), PD->getParameterName(), PD->getDeclContext());
   Clone->DefaultValueAndFlags.setPointerAndInt(
       nullptr, PD->DefaultValueAndFlags.getInt());
   Clone->Bits.ParamDecl.defaultArgumentKind =
diff --git a/test/DebugInfo/Inputs/curry_thunk_other.swift b/test/DebugInfo/Inputs/curry_thunk_other.swift
new file mode 100644
index 0000000000000..914596bdfbc75
--- /dev/null
+++ b/test/DebugInfo/Inputs/curry_thunk_other.swift
@@ -0,0 +1,7 @@
+public struct HTTPMethod {
+  public let rawValue: String
+
+  public init(rawValue: String) {
+    self.rawValue = rawValue
+  }
+}
diff --git a/test/DebugInfo/curry_thunk.swift b/test/DebugInfo/curry_thunk.swift
new file mode 100644
index 0000000000000..3197a6a78ac17
--- /dev/null
+++ b/test/DebugInfo/curry_thunk.swift
@@ -0,0 +1,8 @@
+// RUN: %target-swift-frontend -primary-file %s %S/Inputs/curry_thunk_other.swift -emit-ir -g -o - | %FileCheck %s
+
+public func testCurryThunk() -> [HTTPMethod] {
+  return ["asdf"].map(HTTPMethod.init)
+}
+
+// CHECK: [[FILE:![0-9]+]] = !DIFile(filename: "{{.*}}/curry_thunk.swift", directory: "{{.*}}")
+// CHECK: {{![0-9]+}} = !DILocalVariable(name: "rawValue", arg: 1, scope: {{![0-9]+}}, file: {{![0-9]+}}, type: {{![0-9]+}}, flags: DIFlagArtificial)