Index: lib/Sema/SemaOpenMP.cpp
===================================================================
--- lib/Sema/SemaOpenMP.cpp
+++ lib/Sema/SemaOpenMP.cpp
@@ -1992,9 +1992,18 @@
   return ActOnCapturedRegionEnd(S.get());
 }
 
+static bool HasSimdClause(const ArrayRef<OMPClause *> Clauses) {
+  for (auto *C : Clauses) {
+    if (C->getClauseKind() == OMPC_simd)
+      return true;
+  }
+  return false;
+}
+
 static bool CheckNestingOfRegions(Sema &SemaRef, DSAStackTy *Stack,
                                   OpenMPDirectiveKind CurrentRegion,
                                   const DeclarationNameInfo &CurrentName,
+                                  const ArrayRef<OMPClause *> Clauses,
                                   OpenMPDirectiveKind CancelRegion,
                                   SourceLocation StartLoc) {
   // Allowed nesting of constructs
@@ -2940,8 +2949,9 @@
       ShouldBeInTargetRegion,
       ShouldBeInTeamsRegion
     } Recommend = NoRecommend;
-    if (isOpenMPSimdDirective(ParentRegion) && CurrentRegion != OMPD_ordered &&
-        CurrentRegion != OMPD_simd) {
+    if (isOpenMPSimdDirective(ParentRegion) &&
+        (CurrentRegion != OMPD_ordered ||
+         (CurrentRegion == OMPD_ordered && !HasSimdClause(Clauses)))) {
       // OpenMP [2.16, Nesting of Regions]
       // OpenMP constructs may not be nested inside a simd region.
       // OpenMP [2.8.1,simd Construct, Restrictions]
@@ -3207,8 +3217,8 @@
     OpenMPDirectiveKind CancelRegion, ArrayRef<OMPClause *> Clauses,
     Stmt *AStmt, SourceLocation StartLoc, SourceLocation EndLoc) {
   StmtResult Res = StmtError();
-  if (CheckNestingOfRegions(*this, DSAStack, Kind, DirName, CancelRegion,
-                            StartLoc))
+  if (CheckNestingOfRegions(*this, DSAStack, Kind, DirName, Clauses,
+                            CancelRegion, StartLoc))
     return StmtError();
 
   llvm::SmallVector<OMPClause *, 8> ClausesWithImplicit;
Index: test/OpenMP/nesting_of_regions.cpp
===================================================================
--- test/OpenMP/nesting_of_regions.cpp
+++ test/OpenMP/nesting_of_regions.cpp
@@ -153,7 +153,7 @@
   }
 #pragma omp simd
   for (int i = 0; i < 10; ++i) {
-#pragma omp simd
+#pragma omp simd // expected-error {{OpenMP constructs may not be nested inside a simd region}}
     for (int i = 0; i < 10; ++i)
       ;
   }
@@ -516,7 +516,7 @@
   }
 #pragma omp for simd
   for (int i = 0; i < 10; ++i) {
-#pragma omp simd
+#pragma omp simd // expected-error {{OpenMP constructs may not be nested inside a simd region}}
     for (int i = 0; i < 10; ++i)
       ;
   }
@@ -1902,7 +1902,7 @@
   }
 #pragma omp parallel for simd
   for (int i = 0; i < 10; ++i) {
-#pragma omp simd
+#pragma omp simd // expected-error {{OpenMP constructs may not be nested inside a simd region}}
     for (int i = 0; i < 10; ++i)
       ;
   }
@@ -4314,7 +4314,7 @@
   }
 #pragma omp simd
   for (int i = 0; i < 10; ++i) {
-#pragma omp simd
+#pragma omp simd // expected-error {{OpenMP constructs may not be nested inside a simd region}}
     for (int i = 0; i < 10; ++i)
       ;
   }
@@ -4662,7 +4662,7 @@
   }
 #pragma omp for simd
   for (int i = 0; i < 10; ++i) {
-#pragma omp simd
+#pragma omp simd // expected-error {{OpenMP constructs may not be nested inside a simd region}}
     for (int i = 0; i < 10; ++i)
       ;
   }
@@ -6022,7 +6022,7 @@
   }
 #pragma omp parallel for simd
   for (int i = 0; i < 10; ++i) {
-#pragma omp simd
+#pragma omp simd // expected-error {{OpenMP constructs may not be nested inside a simd region}}
     for (int i = 0; i < 10; ++i)
       ;
   }