diff --git a/clang/lib/CodeGen/CGStmtOpenMP.cpp b/clang/lib/CodeGen/CGStmtOpenMP.cpp
index 02d4f6b3c315..acc3261a1fe6 100644
--- a/clang/lib/CodeGen/CGStmtOpenMP.cpp
+++ b/clang/lib/CodeGen/CGStmtOpenMP.cpp
@@ -5612,6 +5612,7 @@ static void emitOMPAtomicExpr(CodeGenFunction &CGF, OpenMPClauseKind Kind,
   case OMPC_notinbranch:
   case OMPC_link:
   case OMPC_use:
+  case OMPC_novariants:
     llvm_unreachable("Clause is not allowed in 'omp atomic'.");
   }
 }