diff --git a/src/gsm/iuup.c b/src/gsm/iuup.c
index 159e533..b838dc6 100644
--- a/src/gsm/iuup.c
+++ b/src/gsm/iuup.c
@@ -493,7 +493,7 @@
 	struct iuup_ctrl_init_tail *itail;
 	enum iuup_error_cause err_cause;
 	uint8_t num_rfci = 0;
-	unsigned int i;
+	int i;
 	bool is_last;
 	uint16_t remote_mask, match_mask;
 	struct osmo_iuup_tnl_prim *resp;