diff --git a/src/transports/inproc/sinproc.c b/src/transports/inproc/sinproc.c
index d5a4b64..9751593 100644
--- a/src/transports/inproc/sinproc.c
+++ b/src/transports/inproc/sinproc.c
@@ -236,6 +236,8 @@
                 self->state = NN_SINPROC_STATE_STOPPING;
             }
             return;
+        default:
+            break;
         }
     case NN_SINPROC_SRC_PEER:
         switch (type) {
diff --git a/src/transports/ipc/sipc.c b/src/transports/ipc/sipc.c
index 0296073..dba417a 100644
--- a/src/transports/ipc/sipc.c
+++ b/src/transports/ipc/sipc.c
@@ -375,6 +375,7 @@
 
                 default:
                     nn_assert (0);
+                    return;
                 }
 
             case NN_USOCK_SHUTDOWN:
diff --git a/src/transports/utils/streamhdr.c b/src/transports/utils/streamhdr.c
index 1ce1c05..f174bde 100644
--- a/src/transports/utils/streamhdr.c
+++ b/src/transports/utils/streamhdr.c
@@ -237,6 +237,7 @@
                 return;
             default:
                 nn_assert (0);
+                return;
             }
 
         case NN_STREAMHDR_SRC_TIMER: