diff --git a/libfreedv/freedv_api.cpp b/libfreedv/freedv_api.cpp
index 2f1d7865c..db29cb9d0 100644
--- a/libfreedv/freedv_api.cpp
+++ b/libfreedv/freedv_api.cpp
@@ -187,7 +187,8 @@ struct freedv *freedv_open_advanced(int mode, struct freedv_advanced *adv) {
             codec2_mode = CODEC2_MODE_700C;
             break;
         default:
-            assert(0);
+            codec2_mode = CODEC2_MODE_700C;
+            fprintf(stderr, "FreeDV::freedv_open_advanced: unknown mode default to FREEDV_MODE_700C");
         }
 
         f->cohpsk = cohpsk_create();
@@ -932,7 +933,7 @@ static void freedv_comptx_700(struct freedv *f, COMP mod_out[]) {
             break;
         default:
             nspare = 0;
-            assert(0);
+            fprintf(stderr, "FreeDV::freedv_comptx_700: unknown mode default to nspare = 0");
         }
 
         data_flag_index = codec2_get_spare_bit_index(f->codec2);
@@ -1674,7 +1675,7 @@ static int freedv_comprx_700(struct freedv *f, COMP demod_in_8kHz[], int *valid)
                     break;
                 default:
                     nspare = 0;
-                    assert(0);
+                    fprintf(stderr, "FreeDV::freedv_comprx_700: unknown mode default to nspare = 0");
                 }
 
                 for(k=0; k<nspare; k++)  {
diff --git a/libfreedv/gp_interleaver.cpp b/libfreedv/gp_interleaver.cpp
index 5a34b3b82..47654cece 100644
--- a/libfreedv/gp_interleaver.cpp
+++ b/libfreedv/gp_interleaver.cpp
@@ -76,7 +76,7 @@ int choose_interleaver_b(int Nbits)
 
     /* if we get it means a Nbits we dont have in our table so choke */
 
-    assert(0);
+    fprintf(stderr, "FreeDV::choose_interleaver_b: Nbits not in table return 0 as default");
     return 0;
 }
 
diff --git a/libfreedv/ofdm.cpp b/libfreedv/ofdm.cpp
index 102c36b8b..43cce33f1 100644
--- a/libfreedv/ofdm.cpp
+++ b/libfreedv/ofdm.cpp
@@ -1534,7 +1534,8 @@ void ofdm_set_sync(struct OFDM *ofdm, Sync sync_cmd) {
             ofdm->sync_mode = manualsync;
             break;
         default:
-            assert(0);
+            fprintf(stderr, "FreeDV::ofdm_set_sync: unknnown sync mode default to autosync");
+            ofdm->sync_mode = autosync;
     }
 }