diff --git a/src/stringprintf.h b/src/stringprintf.h
index 2e685d1..413fef5 100644
--- a/src/stringprintf.h
+++ b/src/stringprintf.h
@@ -8,11 +8,11 @@
 
 // Returns a string corresponding to printf-like formatting of the arguments.
 std::string StringPrintf(const char* fmt, ...)
-        __attribute__((__format__ (__printf__, 1, 2)));
+        __attribute__((__format__(__printf__, 1, 2)));
 
 // Appends a printf-like formatting of the arguments to 'dst'.
 void StringAppendF(std::string* dst, const char* fmt, ...)
-        __attribute__((__format__ (__printf__, 2, 3)));
+        __attribute__((__format__(__printf__, 2, 3)));
 
 // Appends a printf-like formatting of the arguments to 'dst'.
 void StringAppendV(std::string* dst, const char* format, va_list ap);