diff --git a/clang/lib/Sema/SemaOpenMP.cpp b/clang/lib/Sema/SemaOpenMP.cpp
--- a/clang/lib/Sema/SemaOpenMP.cpp
+++ b/clang/lib/Sema/SemaOpenMP.cpp
@@ -10942,6 +10942,7 @@
             << SourceRange(C->getBeginLoc(), C->getEndLoc());
         Diag(AtomicKindLoc, diag::note_omp_previous_mem_order_clause)
             << getOpenMPClauseName(AtomicKind);
+        return StmtError();
       } else {
         AtomicKind = C->getClauseKind();
         AtomicKindLoc = C->getBeginLoc();
@@ -10958,6 +10959,7 @@
             << SourceRange(C->getBeginLoc(), C->getEndLoc());
         Diag(MemOrderLoc, diag::note_omp_previous_mem_order_clause)
             << getOpenMPClauseName(MemOrderKind);
+        return StmtError();
       } else {
         MemOrderKind = C->getClauseKind();
         MemOrderLoc = C->getBeginLoc();