diff --git a/main/spprintf.h b/main/spprintf.h
index d3c680406a0..a5b10891cca 100644
--- a/main/spprintf.h
+++ b/main/spprintf.h
@@ -41,9 +41,9 @@ PHPAPI size_t spprintf( char **pbuf, size_t max_len, const char *format, ...) PH
 
 PHPAPI size_t vspprintf(char **pbuf, size_t max_len, const char *format, va_list ap) PHP_ATTRIBUTE_FORMAT(printf, 3, 0);
 
-PHPAPI zend_string *vstrpprintf(size_t max_len, const char *format, va_list ap);
+PHPAPI zend_string *vstrpprintf(size_t max_len, const char *format, va_list ap) PHP_ATTRIBUTE_FORMAT(printf, 2, 0);;
 
-PHPAPI zend_string *strpprintf(size_t max_len, const char *format, ...);
+PHPAPI zend_string *strpprintf(size_t max_len, const char *format, ...) PHP_ATTRIBUTE_FORMAT(printf, 2, 3);
 END_EXTERN_C()
 
 #endif /* SNPRINTF_H */