diff --git a/builtin/common/misc_helpers.lua b/builtin/common/misc_helpers.lua
index d2356b505..467f18804 100644
--- a/builtin/common/misc_helpers.lua
+++ b/builtin/common/misc_helpers.lua
@@ -254,7 +254,7 @@ local formspec_escapes = {
 }
 function core.formspec_escape(text)
 	-- Use explicit character set instead of dot here because it doubles the performance
-	return text and text:gsub("[\\%[%];,]", formspec_escapes)
+	return text and string.gsub(text, "[\\%[%];,]", formspec_escapes)
 end