diff --git a/src/coding/gsm0503_coding.c b/src/coding/gsm0503_coding.c
index 835a18e..493f957 100644
--- a/src/coding/gsm0503_coding.c
+++ b/src/coding/gsm0503_coding.c
@@ -543,10 +543,11 @@
 
 	res = osmo_conv_decode(code, input, output);
 
-	if (n_bits_total || n_errors) {
-		coded_len = osmo_conv_encode(code, output, recoded);
-		OSMO_ASSERT(sizeof(recoded) / sizeof(recoded[0]) >= coded_len);
-	}
+	if (!n_bits_total && !n_errors)
+		return res;
+
+	coded_len = osmo_conv_encode(code, output, recoded);
+	OSMO_ASSERT(sizeof(recoded) / sizeof(recoded[0]) >= coded_len);
 
 	/* Count bit errors */
 	if (n_errors) {