diff --git a/ext/standard/php_smart_str.h b/ext/standard/php_smart_str.h
index 3fbee5d9424..2f245bbc0eb 100644
--- a/ext/standard/php_smart_str.h
+++ b/ext/standard/php_smart_str.h
@@ -35,11 +35,11 @@
 } while (0)
 
 #ifndef SMART_STR_PREALLOC
-#define SMART_STR_PREALLOC 128
+#define SMART_STR_PREALLOC 4096
 #endif
 
 #ifndef SMART_STR_START_SIZE
-#define SMART_STR_START_SIZE 78
+#define SMART_STR_START_SIZE 1024
 #endif
 
 #ifdef SMART_STR_USE_REALLOC