diff --git a/core/core.h b/core/core.h
index b73a00c1..a5cd6d0e 100644
--- a/core/core.h
+++ b/core/core.h
@@ -297,14 +297,14 @@ char* String_cstr(string *s) {
 }
 
 string String_str(string *s) {
-    int n = strlen(*s) + 4;
+    int n = strlen(*s) + 1;
     string buffer = CARP_MALLOC(n);
     snprintf(buffer, n, "%s", *s);
     return buffer;
 }
 
 string String_prn(string *s) {
-    int n = strlen(*s) + 1;
+    int n = strlen(*s) + 4;
     string buffer = CARP_MALLOC(n);
     snprintf(buffer, n, "@\"%s\"", *s);
     return buffer;