diff --git a/releasenotes.md b/releasenotes.md
index 9be7e2de8..2752ac3d9 100644
--- a/releasenotes.md
+++ b/releasenotes.md
@@ -6,7 +6,7 @@
 - None yet.
 
 ### Fixes
-- None yet.
+- Fix issue requiring prefix on a generic interface declaration.
 
 ### Stdlib changes
 - Added '%h' and '%H' for printing out binary data in hexadecimal using the formatter.
diff --git a/src/compiler/compiler_internal.h b/src/compiler/compiler_internal.h
index 598f7865a..258bf95f9 100644
--- a/src/compiler/compiler_internal.h
+++ b/src/compiler/compiler_internal.h
@@ -3214,7 +3214,9 @@ INLINE bool decl_is_user_defined_type(Decl *decl)
 {
 	DeclKind kind = decl->decl_kind;
 	return (kind == DECL_UNION) | (kind == DECL_STRUCT) | (kind == DECL_BITSTRUCT)
-			| (kind == DECL_ENUM) | (kind == DECL_TYPEDEF) || (kind == DECL_DISTINCT);
+			| (kind == DECL_ENUM) | (kind == DECL_TYPEDEF) | (kind == DECL_DISTINCT)
+			| (kind == DECL_INTERFACE)
+			;
 }
 
 INLINE Decl *decl_flatten(Decl *decl)
diff --git a/test/test_suite/any/generic_interface.c3 b/test/test_suite/any/generic_interface.c3
new file mode 100644
index 000000000..6bd257af5
--- /dev/null
+++ b/test/test_suite/any/generic_interface.c3
@@ -0,0 +1,12 @@
+module foo(<Type>);
+
+interface Baz
+{}
+
+module test;
+import foo;
+
+fn void main()
+{
+	Baz(<int>) x;
+}