diff --git a/src/libbsc/bsc_api.c b/src/libbsc/bsc_api.c
index bd55dfc..3592c00 100644
--- a/src/libbsc/bsc_api.c
+++ b/src/libbsc/bsc_api.c
@@ -357,7 +357,11 @@
 		 * an explicit override by the 'full_rate' argument */
 		switch (lchan->type) {
 		case GSM_LCHAN_TCH_F:
-			return 1;
+			if (full_rate)
+				return 1;
+			else
+				return 0;
+			break;
 		case GSM_LCHAN_TCH_H:
 			if (full_rate)
 				return 0;