diff --git a/clang/lib/Parse/BSC/ParseDeclBSC.cpp b/clang/lib/Parse/BSC/ParseDeclBSC.cpp
index e83e2b6e780306ad6917296833bb71d1d6081514..78b1a3093240c16aea1ab7c6059199805562c88e 100644
--- a/clang/lib/Parse/BSC/ParseDeclBSC.cpp
+++ b/clang/lib/Parse/BSC/ParseDeclBSC.cpp
@@ -555,7 +555,7 @@ Parser::DeclGroupPtrTy Parser::ParseImplTraitDeclaration() {
       Trait = TTD->getTemplatedDecl();
     }
   }
-  if (!Trait) {
+  if (!Trait || Trait->isInvalidDecl() || !Trait->isCompleteDefinition()) {
     Diag(Tok.getLocation(), diag::err_unexpected_token_for_impl_trait_decl);
     SkipUntil(tok::semi);
     return nullptr;
diff --git a/clang/test/BSC/Negative/Trait/GenericTrait/partitially_define/partitially_define.cbs b/clang/test/BSC/Negative/Trait/GenericTrait/partitially_define/partitially_define.cbs
new file mode 100644
index 0000000000000000000000000000000000000000..1086e97f5d31f492f651c62db6ac085b703eefb8
--- /dev/null
+++ b/clang/test/BSC/Negative/Trait/GenericTrait/partitially_define/partitially_define.cbs
@@ -0,0 +1,7 @@
+// RUN: %clang_cc1 -fsyntax-only -verify %s
+
+trait T; // expected-error {{invalid syntax, semi not expected after 'trait T'}}
+impl trait T for int; // expected-error {{unexpected token for ImplTraitDecl}}
+
+trait T*; // expected-error {{expected identifier or '('}}
+impl trait T for int; // expected-error {{unexpected token for ImplTraitDecl}}
\ No newline at end of file