diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_posix.h b/compiler-rt/lib/sanitizer_common/sanitizer_posix.h
--- a/compiler-rt/lib/sanitizer_common/sanitizer_posix.h
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_posix.h
@@ -20,10 +20,7 @@
 #include "sanitizer_platform_limits_posix.h"
 #include "sanitizer_platform_limits_solaris.h"
 
-#if !SANITIZER_POSIX
-// Make it hard to accidentally use any of functions declared in this file:
-#error This file should only be included on POSIX
-#endif
+#if SANITIZER_POSIX
 
 namespace __sanitizer {
 
@@ -126,4 +123,6 @@
 
 }  // namespace __sanitizer
 
+#endif  // SANITIZER_POSIX
+
 #endif  // SANITIZER_POSIX_H