diff --git a/src/Magnum/Platform/NaClApplication.h b/src/Magnum/Platform/NaClApplication.h
index d134c5560..efcb7d80f 100644
--- a/src/Magnum/Platform/NaClApplication.h
+++ b/src/Magnum/Platform/NaClApplication.h
@@ -48,6 +48,10 @@ namespace pp {
     class Fullscreen;
 }
 
+#ifndef CORRADE_TARGET_NACL
+#error This header is available only on Google Chrome Native Client
+#endif
+
 namespace Magnum { namespace Platform {
 
 /** @nosubgrouping