diff --git a/app/dtmf.c b/app/dtmf.c
index 0be3e76..d95cbdf 100644
--- a/app/dtmf.c
+++ b/app/dtmf.c
@@ -203,7 +203,7 @@ void DTMF_Append(const char code)
 void DTMF_HandleRequest(void)
 {	// proccess the RX'ed DTMF characters
 
-	char         String[20];
+	char         String[21];
 	unsigned int Offset;
 
 	if (!gDTMF_RX_pending)
@@ -383,7 +383,7 @@ void DTMF_HandleRequest(void)
 void DTMF_Reply(void)
 {
 	uint16_t    Delay;
-	char        String[20];
+	char        String[23];
 	const char *pString = NULL;
 
 	switch (gDTMF_ReplyState)
diff --git a/ui/main.c b/ui/main.c
index f773956..2f6db32 100644
--- a/ui/main.c
+++ b/ui/main.c
@@ -271,7 +271,7 @@ void UI_DisplayMain(void)
 {
 	const unsigned int line0 = 0;  // text screen line
 	const unsigned int line1 = 4;
-	char               String[16];
+	char               String[22];
 	unsigned int       vfo_num;
 
 	center_line = CENTER_LINE_NONE;