diff --git a/src/libmsc/msc_a.c b/src/libmsc/msc_a.c
index 4fa9676..38f05a6 100644
--- a/src/libmsc/msc_a.c
+++ b/src/libmsc/msc_a.c
@@ -1464,6 +1464,15 @@
 	if (codec_if_known) {
 		const struct codec_mapping *codec_assigned;
 
+		/* Check for unexpected codec with CSD */
+		if (cc_trans->bearer_cap.transfer == GSM48_BCAP_ITCAP_UNR_DIG_INF &&
+		    codec_if_known->type != GSM0808_SCT_CSD) {
+			LOG_TRANS(cc_trans, LOGL_ERROR, "Unexpected codec in Assignment Complete for CSD: %s\n",
+				  gsm0808_speech_codec_type_name(codec_if_known->type));
+			call_leg_release(msc_a->cc.call_leg);
+			return;
+		}
+
 		/* For 2G:
 		 * - The Assignment Complete has returned a specific codec (e.g. FR3 for AMR FR).
 		 * - Set this codec at the MGW endpoint facing the RAN.
@@ -1486,15 +1495,6 @@
 			return;
 		}
 
-		/* Check for unexpected codec with CSD */
-		if (cc_trans->bearer_cap.transfer == GSM48_BCAP_ITCAP_UNR_DIG_INF &&
-		    codec_if_known->type != GSM0808_SCT_CSD) {
-			LOG_TRANS(cc_trans, LOGL_ERROR, "Unexpected codec in Assignment Complete for CSD: %s\n",
-				  gsm0808_speech_codec_type_name(codec_if_known->type));
-			call_leg_release(msc_a->cc.call_leg);
-			return;
-		}
-
 		/* Update RAN-side endpoint CI from Assignment result -- unless it is forced by the ran_infra, in which
 		 * case it remains unchanged as passed to the earlier call of call_leg_ensure_ci(). */
 		if (msc_a->c.ran->force_mgw_codecs_to_ran.count == 0)