diff --git a/clang/lib/Headers/opencl-c-base.h b/clang/lib/Headers/opencl-c-base.h
index 19aaa90c1a74..a82954ddd326 100644
--- a/clang/lib/Headers/opencl-c-base.h
+++ b/clang/lib/Headers/opencl-c-base.h
@@ -297,8 +297,11 @@ typedef enum memory_scope {
  * image memory.
  */
 #define CLK_IMAGE_MEM_FENCE  0x04
-#endif //__OPENCL_C_VERSION__ >= CL_VERSION_2_0
 
+#ifndef ATOMIC_VAR_INIT
+#define ATOMIC_VAR_INIT(x) (x)
+#endif //ATOMIC_VAR_INIT
+#define ATOMIC_FLAG_INIT 0
 
 // enum values aligned with what clang uses in EmitAtomicExpr()
 typedef enum memory_order
@@ -310,6 +313,8 @@ typedef enum memory_order
   memory_order_seq_cst = __ATOMIC_SEQ_CST
 } memory_order;
 
+#endif //__OPENCL_C_VERSION__ >= CL_VERSION_2_0
+
 // OpenCL v1.1 s6.11.3, v1.2 s6.12.14, v2.0 s6.13.14 - Image Read and Write Functions
 
 // These values need to match the runtime equivalent
diff --git a/clang/test/Headers/opencl-c-header.cl b/clang/test/Headers/opencl-c-header.cl
index d65a219da30a..8183a8c1f79a 100644
--- a/clang/test/Headers/opencl-c-header.cl
+++ b/clang/test/Headers/opencl-c-header.cl
@@ -80,6 +80,10 @@ void test_atomics(__generic volatile unsigned int* a) {
 }
 #endif
 
+// Verify that ATOMIC_VAR_INIT is defined.
+#if defined(__OPENCL_CPP_VERSION__) || (__OPENCL_C_VERSION__ >= CL_VERSION_2_0)
+global atomic_int z = ATOMIC_VAR_INIT(99);
+#endif //__OPENCL_C_VERSION__
 
 // Verify that non-builtin cl_intel_planar_yuv extension is defined from
 // OpenCL 1.2 onwards.