Index: clang/include/clang/Basic/DiagnosticSemaKinds.td
===================================================================
--- clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -8756,8 +8756,6 @@
 def warn_omp_alignment_not_power_of_two : Warning<
   "aligned clause will be ignored because the requested alignment is not a power of 2">,
   InGroup<OpenMPClauses>;
-def err_omp_enclosed_declare_target : Error<
-  "declare target region may not be enclosed within another declare target region">;
 def err_omp_invalid_target_decl : Error<
   "%0 used in declare target directive is not a variable or a function name">;
 def err_omp_declare_target_multiple : Error<
Index: clang/include/clang/Sema/Sema.h
===================================================================
--- clang/include/clang/Sema/Sema.h
+++ clang/include/clang/Sema/Sema.h
@@ -8616,8 +8616,8 @@
   //
 private:
   void *VarDataSharingAttributesStack;
-  /// Set to true inside '#pragma omp declare target' region.
-  bool IsInOpenMPDeclareTargetContext = false;
+  /// Number of nested '#pragma omp declare target' directives.
+  unsigned DeclareTargetNestingLevel = 0;
   /// Initialization of data-sharing attributes stack.
   void InitDataSharingAttributesStack();
   void DestroyDataSharingAttributesStack();
@@ -8751,7 +8751,7 @@
                                    SourceLocation IdLoc = SourceLocation());
   /// Return true inside OpenMP declare target region.
   bool isInOpenMPDeclareTargetContext() const {
-    return IsInOpenMPDeclareTargetContext;
+    return DeclareTargetNestingLevel > 0;
   }
   /// Return true inside OpenMP target region.
   bool isInOpenMPTargetExecutionDirective() const;
Index: clang/lib/Sema/SemaOpenMP.cpp
===================================================================
--- clang/lib/Sema/SemaOpenMP.cpp
+++ clang/lib/Sema/SemaOpenMP.cpp
@@ -12870,19 +12870,14 @@
     Diag(Loc, diag::err_omp_region_not_file_context);
     return false;
   }
-  if (IsInOpenMPDeclareTargetContext) {
-    Diag(Loc, diag::err_omp_enclosed_declare_target);
-    return false;
-  }
-
-  IsInOpenMPDeclareTargetContext = true;
+  ++DeclareTargetNestingLevel;
   return true;
 }
 
 void Sema::ActOnFinishOpenMPDeclareTargetDirective() {
-  assert(IsInOpenMPDeclareTargetContext &&
+  assert(DeclareTargetNestingLevel > 0 &&
          "Unexpected ActOnFinishOpenMPDeclareTargetDirective");
-  IsInOpenMPDeclareTargetContext = false;
+  --DeclareTargetNestingLevel;
 }
 
 void Sema::ActOnOpenMPDeclareTargetName(Scope *CurScope,
Index: clang/test/OpenMP/Inputs/declare_target_include.h
===================================================================
--- /dev/null
+++ clang/test/OpenMP/Inputs/declare_target_include.h
@@ -0,0 +1,3 @@
+#pragma omp declare target
+  void zyx();
+#pragma omp end declare target
Index: clang/test/OpenMP/declare_target_ast_print.cpp
===================================================================
--- clang/test/OpenMP/declare_target_ast_print.cpp
+++ clang/test/OpenMP/declare_target_ast_print.cpp
@@ -1,10 +1,10 @@
-// RUN: %clang_cc1 -verify -fopenmp -ast-print %s | FileCheck %s
-// RUN: %clang_cc1 -fopenmp -x c++ -std=c++11 -emit-pch -o %t %s
-// RUN: %clang_cc1 -fopenmp -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print | FileCheck %s
+// RUN: %clang_cc1 -verify -fopenmp -I %S/Inputs -ast-print %s | FileCheck %s
+// RUN: %clang_cc1 -fopenmp -x c++ -std=c++11 -I %S/Inputs -emit-pch -o %t %s
+// RUN: %clang_cc1 -fopenmp -std=c++11 -include-pch %t -fsyntax-only -I %S/Inputs -verify %s -ast-print | FileCheck %s
 
-// RUN: %clang_cc1 -verify -fopenmp-simd -ast-print %s | FileCheck %s
-// RUN: %clang_cc1 -fopenmp-simd -x c++ -std=c++11 -emit-pch -o %t %s
-// RUN: %clang_cc1 -fopenmp-simd -std=c++11 -include-pch %t -fsyntax-only -verify %s -ast-print | FileCheck %s
+// RUN: %clang_cc1 -verify -fopenmp-simd -I %S/Inputs -ast-print %s | FileCheck %s
+// RUN: %clang_cc1 -fopenmp-simd -x c++ -std=c++11 -I %S/Inputs -emit-pch -o %t %s
+// RUN: %clang_cc1 -fopenmp-simd -std=c++11 -include-pch %t -fsyntax-only -I %S/Inputs -verify %s -ast-print | FileCheck %s
 // expected-no-diagnostics
 
 #ifndef HEADER
@@ -169,6 +169,32 @@
 // CHECK: #pragma omp end declare target
 // CHECK: int b;
 
+#pragma omp declare target
+  #include "declare_target_include.h"
+  void xyz();
+#pragma omp end declare target
+
+// CHECK: #pragma omp declare target
+// CHECK: void zyx();
+// CHECK: #pragma omp end declare target
+// CHECK: #pragma omp declare target
+// CHECK: void xyz();
+// CHECK: #pragma omp end declare target
+
+#pragma omp declare target
+  #pragma omp declare target
+    void abc();
+  #pragma omp end declare target
+  void cba();
+#pragma omp end declare target
+
+// CHECK: #pragma omp declare target
+// CHECK: void abc();
+// CHECK: #pragma omp end declare target
+// CHECK: #pragma omp declare target
+// CHECK: void cba();
+// CHECK: #pragma omp end declare target
+
 int main (int argc, char **argv) {
   foo();
   foo_c();
Index: clang/test/OpenMP/declare_target_messages.cpp
===================================================================
--- clang/test/OpenMP/declare_target_messages.cpp
+++ clang/test/OpenMP/declare_target_messages.cpp
@@ -59,8 +59,19 @@
   }
 }
 
+#pragma omp declare target
+  void abc();
+#pragma omp end declare target
+void cba();
+#pragma omp end declare target // expected-error {{unexpected OpenMP directive '#pragma omp end declare target'}}
 
-#pragma omp declare target // expected-note {{to match this '#pragma omp declare target'}}
+#pragma omp declare target  // expected-note {{to match this '#pragma omp declare target'}}
+  #pragma omp declare target
+    void def();
+  #pragma omp end declare target
+  void fed();
+
+#pragma omp declare target // expected-note {{to match this '#pragma omp declare target'}} // expected-error {{expected '#pragma omp end declare target'}}
 #pragma omp threadprivate(a) // expected-note {{defined as threadprivate or thread local}}
 extern int b;
 int g;