diff --git a/vlib/strings/builder.c.v b/vlib/strings/builder.c.v
index 9c46523e0e..2e7e7b1bb0 100644
--- a/vlib/strings/builder.c.v
+++ b/vlib/strings/builder.c.v
@@ -179,7 +179,7 @@ pub fn (mut b Builder) str() string {
 // ensure_cap ensures that the buffer has enough space for at least `n` bytes by growing the buffer if necessary
 pub fn (mut b Builder) ensure_cap(n int) {
 	// code adapted from vlib/builtin/array.v
-	if n < 0 || n <= b.cap {
+	if n <= b.cap {
 		return
 	}