diff --git a/gril/grilutil.c b/gril/grilutil.c
index cf34d53a..d210abad 100644
--- a/gril/grilutil.c
+++ b/gril/grilutil.c
@@ -60,24 +60,6 @@ int ril_protocol_string_to_ofono_protocol(gchar *protocol_str)
 	return result;
 }
 
-const char *ril_authtype_to_string(int auth_type)
-{
-	switch (auth_type) {
-	case RIL_AUTH_NONE:
-		return "NONE";
-	case RIL_AUTH_PAP:
-		return "PAP";
-	case RIL_AUTH_CHAP:
-		return "CHAP";
-	case RIL_AUTH_BOTH:
-		return "BOTH";
-	case RIL_AUTH_ANY:
-		return "ANY";
-	default:
-		return "<INVALID>";
-	}
-}
-
 const char *ril_cardstate_to_string(int card_state)
 {
 	switch (card_state) {
diff --git a/gril/grilutil.h b/gril/grilutil.h
index a6915d44..152a84d6 100644
--- a/gril/grilutil.h
+++ b/gril/grilutil.h
@@ -32,7 +32,6 @@ extern "C" {
 #include "gril.h"
 
 int ril_protocol_string_to_ofono_protocol(gchar *protocol_str);
-const char *ril_authtype_to_string(int auth_type);
 const char *ril_cardstate_to_string(int card_state);
 const char *ril_error_to_string(int error);
 const char *ril_pinstate_to_string(int pin_state);