diff --git a/app/dtmf.c b/app/dtmf.c
index 45aa198..6ea401d 100644
--- a/app/dtmf.c
+++ b/app/dtmf.c
@@ -55,7 +55,7 @@ bool              gDTMF_IsGroupCall;
 
 bool DTMF_ValidateCodes(char *pCode, uint8_t Size)
 {
-	uint8_t i;
+	unsigned int i;
 
 	if (pCode[0] == 0xFF || pCode[0] == 0)
 		return false;
@@ -75,19 +75,26 @@ bool DTMF_ValidateCodes(char *pCode, uint8_t Size)
 	return true;
 }
 
-bool DTMF_GetContact(uint8_t Index, char *pContact)
+bool DTMF_GetContact(const int Index, char *pContact)
 {
-	EEPROM_ReadBuffer(0x1C00 + (Index * 16), pContact, 16);
-	return ((pContact[0] - ' ') >= 0x5F) ? false : true;
+	int i = -1;
+	if (Index >= 0 && Index < 16 && pContact != NULL)  // max 16 DTMF contacts
+	{
+		EEPROM_ReadBuffer(0x1C00 + (Index * 16), pContact, 16);
+		i = (int)pContact[0] - ' ';
+	}
+	return (i < 0 || i >= 95) ? false : true;
 }
 
 bool DTMF_FindContact(const char *pContact, char *pResult)
 {
 	char Contact [16];
-	uint8_t i, j;
+	unsigned int i;
 
 	for (i = 0; i < 16; i++)
 	{
+		unsigned int j;
+
 		if (!DTMF_GetContact(i, Contact))
 			return false;
 
@@ -139,7 +146,7 @@ char DTMF_GetCharacter(uint8_t Code)
 
 bool DTMF_CompareMessage(const char *pMsg, const char *pTemplate, uint8_t Size, bool bCheckGroup)
 {
-	uint8_t i;
+	unsigned int i;
 
 	for (i = 0; i < Size; i++)
 	{
diff --git a/app/dtmf.h b/app/dtmf.h
index 2227e7b..02c1a6c 100644
--- a/app/dtmf.h
+++ b/app/dtmf.h
@@ -77,7 +77,7 @@ extern bool gDTMF_IsTx;
 extern uint8_t gDTMF_TxStopCountdown;
 
 bool DTMF_ValidateCodes(char *pCode, uint8_t Size);
-bool DTMF_GetContact(uint8_t Index, char *pContact);
+bool DTMF_GetContact(const int Index, char *pContact);
 bool DTMF_FindContact(const char *pContact, char *pResult);
 char DTMF_GetCharacter(uint8_t Code);
 bool DTMF_CompareMessage(const char *pDTMF, const char *pTemplate, uint8_t Size, bool bFlag);
diff --git a/firmware b/firmware
index 034580a..7763c96 100644
Binary files a/firmware and b/firmware differ
diff --git a/firmware.bin b/firmware.bin
index 9d02dfd..882bd6d 100644
Binary files a/firmware.bin and b/firmware.bin differ
diff --git a/firmware.packed.bin b/firmware.packed.bin
index 48c43b9..26effc7 100644
Binary files a/firmware.packed.bin and b/firmware.packed.bin differ
diff --git a/ui/menu.c b/ui/menu.c
index 6ca8af8..3bfe237 100644
--- a/ui/menu.c
+++ b/ui/menu.c
@@ -509,10 +509,9 @@ void UI_DisplayMenu(void)
 			break;
 	
 		case MENU_D_LIST:
-			gIsDtmfContactValid = DTMF_GetContact((uint8_t)gSubMenuSelection - 1, Contact);
+			gIsDtmfContactValid = DTMF_GetContact((int)gSubMenuSelection - 1, Contact);
 			if (!gIsDtmfContactValid)
-				// Ghidra being weird again...
-				memcpy(String, "NULL\0\0\0", 8);
+				strcpy(String, "NULL");
 			else
 				memcpy(String, Contact, 8);
 			break;