diff --git a/iwinfo_nl80211.c b/iwinfo_nl80211.c
index a08d580..1a1fc69 100644
--- a/iwinfo_nl80211.c
+++ b/iwinfo_nl80211.c
@@ -604,7 +604,7 @@ static char * nl80211_phy2ifname(const char *ifname)
 					    ((ifidx < 0) || (cifidx < ifidx)))
 					{
 						ifidx = cifidx;
-						strncpy(nif, e->d_name, sizeof(nif));
+						strncpy(nif, e->d_name, sizeof(nif) - 1);
 					}
 				}
 			}