diff --git a/src/cmd-parser.y b/src/cmd-parser.y
index 0211371..59432a4 100644
--- a/src/cmd-parser.y
+++ b/src/cmd-parser.y
@@ -192,7 +192,7 @@ cluster_stmt		:	CLUSTER		SHOW
 
 portable_stmt		:	PORTABLE	SHOW
 			{
-				char ipei[DECT_IPEI_STRING_LEN];
+				char ipei[DECT_IPEI_STRING_LEN + 1];
 				struct dect_handle_priv *priv;
 				struct dect_pt *pt;
 
diff --git a/src/nwk.c b/src/nwk.c
index 5569c00..267ee7f 100644
--- a/src/nwk.c
+++ b/src/nwk.c
@@ -82,7 +82,7 @@ static FILE *dect_keyfile_open(const char *mode)
 
 static void dect_pt_write_uak(const struct dect_pt *pt)
 {
-	char ipei[DECT_IPEI_STRING_LEN];
+	char ipei[DECT_IPEI_STRING_LEN + 1];
 	unsigned int i;
 	FILE *f;
 
@@ -101,7 +101,7 @@ static void dect_pt_write_uak(const struct dect_pt *pt)
 
 static void dect_pt_read_uak(struct dect_pt *pt)
 {
-	char ipei[DECT_IPEI_STRING_LEN];
+	char ipei[DECT_IPEI_STRING_LEN + 1];
 	uint8_t uak[DECT_AUTH_KEY_LEN];
 	struct dect_ipui ipui;
 	unsigned int i;