diff --git a/bin/mbus-serial-request-data-multi-reply.c b/bin/mbus-serial-request-data-multi-reply.c
index 0f1fb7a..dcdf390 100755
--- a/bin/mbus-serial-request-data-multi-reply.c
+++ b/bin/mbus-serial-request-data-multi-reply.c
@@ -79,7 +79,7 @@ main(int argc, char **argv)
         return 1;
     }
 
-    if (!mbus_connect(handle))
+    if (mbus_connect(handle) == -1)
     {
         printf("Failed to setup connection to M-bus gateway\n");
         return 1;
diff --git a/bin/mbus-serial-scan-secondary.c b/bin/mbus-serial-scan-secondary.c
index b395c63..4b9e120 100755
--- a/bin/mbus-serial-scan-secondary.c
+++ b/bin/mbus-serial-scan-secondary.c
@@ -108,7 +108,7 @@ main(int argc, char **argv)
         return 1;
     }
 
-    if (!mbus_connect(handle))
+    if (mbus_connect(handle) == -1)
     {
         printf("Failed to setup connection to M-bus gateway\n");
         return 1;