diff --git a/common.h b/common.h
index a851306..4228e71 100644
--- a/common.h
+++ b/common.h
@@ -40,7 +40,7 @@
 // fopen a file, mounting volumes and making parent dirs as necessary.
 FILE* fopen_path(const std::string& path, const char* mode);
 
-void ui_print(const char* format, ...);
+void ui_print(const char* format, ...) __printflike(1, 2);
 
 bool is_ro_debuggable();