diff --git a/vlib/builtin/string_interpolation.v b/vlib/builtin/string_interpolation.v
index 0357f9ecbd..ecae53e441 100644
--- a/vlib/builtin/string_interpolation.v
+++ b/vlib/builtin/string_interpolation.v
@@ -694,7 +694,7 @@ pub:
 // interpolation function
 @[direct_array_access; manualfree]
 pub fn str_intp(data_len int, input_base &StrIntpData) string {
-	mut res := strings.new_builder(256)
+	mut res := strings.new_builder(64)
 	for i := 0; i < data_len; i++ {
 		data := unsafe { &input_base[i] }
 		// avoid empty strings