diff --git a/channels/chan_misdn.c b/channels/chan_misdn.c
index 4860ba0a78fa62361d108455a7eeaf4b8e6021a4..6d0e3d89f7ce5892f953cc580e1d38a7cd3cb347 100644
--- a/channels/chan_misdn.c
+++ b/channels/chan_misdn.c
@@ -6970,8 +6970,12 @@ static struct ast_frame *process_ast_dsp(struct chan_list *tmp, struct ast_frame
 		return NULL;
 	}
 
- 	if (!f || (f->frametype != AST_FRAME_DTMF))
- 		return frame;
+	if (!f || (f->frametype != AST_FRAME_DTMF)) {
+		if (f) {
+			ast_frfree(f);
+		}
+		return frame;
+	}
 
 	ast_debug(1, "Detected inband DTMF digit: %c\n", f->subclass);