diff --git a/mlir/lib/ExecutionEngine/AsyncRuntime.cpp b/mlir/lib/ExecutionEngine/AsyncRuntime.cpp
--- a/mlir/lib/ExecutionEngine/AsyncRuntime.cpp
+++ b/mlir/lib/ExecutionEngine/AsyncRuntime.cpp
@@ -359,9 +359,6 @@
 // Export symbols for the MLIR runner integration. All other symbols are hidden.
 #ifndef _WIN32
 #define API __attribute__((visibility("default")))
-#else
-#define API
-#endif // _WIN32
 
 extern "C" API void __mlir_runner_init(llvm::StringMap<void *> &exportSymbols) {
   auto exportSymbol = [&](llvm::StringRef name, auto ptr) {
@@ -407,4 +404,6 @@
 
 extern "C" API void __mlir_runner_destroy() { resetDefaultAsyncRuntime(); }
 
+#endif // _WIN32
+
 #endif // MLIR_ASYNCRUNTIME_DEFINE_FUNCTIONS