diff --git a/selfdrive/pandad/spi.cc b/selfdrive/pandad/spi.cc
index 8f1e29689b6c18..d365dd3620861f 100644
--- a/selfdrive/pandad/spi.cc
+++ b/selfdrive/pandad/spi.cc
@@ -418,7 +418,7 @@ int PandaSpiHandle::spi_transfer(uint8_t endpoint, uint8_t *tx_data, uint16_t tx
     }
   }
 
-  if (ret > 0) ret = -1;
+  if (ret >= 0) ret = -1;
   return ret;
 }
 #endif