diff --git a/ext/pgsql/pgsql.c b/ext/pgsql/pgsql.c
index 442f669f324..6e3c186e54b 100644
--- a/ext/pgsql/pgsql.c
+++ b/ext/pgsql/pgsql.c
@@ -29,6 +29,8 @@
 #include "config.h"
 #endif
 
+#define SMART_STR_PREALLOC 512
+
 #include "php.h"
 #include "php_ini.h"
 #include "ext/standard/php_standard.h"