diff --git a/include/uapi/linux/ethtool.h b/include/uapi/linux/ethtool.h
index 3652b239dad1..d473e5ed044c 100644
--- a/include/uapi/linux/ethtool.h
+++ b/include/uapi/linux/ethtool.h
@@ -1591,7 +1591,7 @@ enum ethtool_link_mode_bit_indices {
 
 static inline int ethtool_validate_speed(__u32 speed)
 {
-	return speed <= INT_MAX || speed == SPEED_UNKNOWN;
+	return speed <= INT_MAX || speed == (__u32)SPEED_UNKNOWN;
 }
 
 /* Duplex, half or full. */