diff --git a/clang/lib/Headers/__clang_cuda_complex_builtins.h b/clang/lib/Headers/__clang_cuda_complex_builtins.h
--- a/clang/lib/Headers/__clang_cuda_complex_builtins.h
+++ b/clang/lib/Headers/__clang_cuda_complex_builtins.h
@@ -16,7 +16,7 @@
 // to work with CUDA and OpenMP target offloading [in C and C++ mode].)
 
 #pragma push_macro("__DEVICE__")
-#ifdef __OPENMP_NVPTX__
+#ifdef _OPENMP
 #pragma omp declare target
 #define __DEVICE__ __attribute__((noinline, nothrow, cold, weak))
 #else
@@ -26,7 +26,7 @@
 // To make the algorithms available for C and C++ in CUDA and OpenMP we select
 // different but equivalent function versions. TODO: For OpenMP we currently
 // select the native builtins as the overload support for templates is lacking.
-#if !defined(__OPENMP_NVPTX__)
+#if !defined(_OPENMP)
 #define _ISNANd std::isnan
 #define _ISNANf std::isnan
 #define _ISINFd std::isinf
@@ -276,7 +276,7 @@
 #undef _fmaxd
 #undef _fmaxf
 
-#ifdef __OPENMP_NVPTX__
+#ifdef _OPENMP
 #pragma omp end declare target
 #endif
 
diff --git a/clang/lib/Headers/openmp_wrappers/complex b/clang/lib/Headers/openmp_wrappers/complex
--- a/clang/lib/Headers/openmp_wrappers/complex
+++ b/clang/lib/Headers/openmp_wrappers/complex
@@ -17,18 +17,12 @@
 // We require std::math functions in the complex builtins below.
 #include <cmath>
 
-#define __CUDA__
-#define __OPENMP_NVPTX__
 #include <__clang_cuda_complex_builtins.h>
-#undef __OPENMP_NVPTX__
 #endif
 
 // Grab the host header too.
 #include_next <complex>
 
-
-#ifdef __cplusplus
-
 // If we are compiling against libc++, the macro _LIBCPP_STD_VER should be set
 // after including <cmath> above. Since the complex header we use is a
 // simplified version of the libc++, we don't need it in this case. If we
@@ -48,5 +42,3 @@
 #pragma omp end declare variant
 
 #endif
-
-#endif
diff --git a/clang/lib/Headers/openmp_wrappers/complex.h b/clang/lib/Headers/openmp_wrappers/complex.h
--- a/clang/lib/Headers/openmp_wrappers/complex.h
+++ b/clang/lib/Headers/openmp_wrappers/complex.h
@@ -17,10 +17,8 @@
 // We require math functions in the complex builtins below.
 #include <math.h>
 
-#define __CUDA__
-#define __OPENMP_NVPTX__
 #include <__clang_cuda_complex_builtins.h>
-#undef __OPENMP_NVPTX__
+
 #endif
 
 // Grab the host header too.