diff --git base/strings/strcat.h base/strings/strcat.h
index b249d49..44c6211 100644
--- base/strings/strcat.h
+++ base/strings/strcat.h
@@ -11,6 +11,12 @@
 #include "base/compiler_specific.h"
 #include "base/containers/span.h"
 #include "base/strings/string_piece.h"
+#include "build/build_config.h"
+
+#if defined(OS_WIN)
+// To resolve a conflict with Win32 API StrCat macro.
+#include "base/win/windows_types.h"
+#endif
 
 namespace base {
 
diff --git base/win/windows_types.h base/win/windows_types.h
index 8060f03..2a86195 100644
--- base/win/windows_types.h
+++ base/win/windows_types.h
@@ -248,5 +248,6 @@
 #define SendMessageCallback SendMessageCallbackW
 #define SetCurrentDirectory SetCurrentDirectoryW
 #define StartService StartServiceW
+#define StrCat StrCatW
 
 #endif  // BASE_WIN_WINDOWS_TYPES_H