diff --git a/agent/hcp/bootstrap/testing.go b/agent/hcp/bootstrap/testing.go
index f073d1718344..b7b5c6cb86ac 100644
--- a/agent/hcp/bootstrap/testing.go
+++ b/agent/hcp/bootstrap/testing.go
@@ -176,7 +176,7 @@ func generateClusterData(cluster resource.Resource) (gnmmod.HashicorpCloudGlobal
 }
 
 func mapArgsString(m map[string]string) string {
-	args := make([]string, len(m))
+	args := make([]string, 0, len(m))
 	for k, v := range m {
 		args = append(args, fmt.Sprintf("%s=%s", k, v))
 	}