diff --git a/src/drivers/pca8574/module.mk b/src/drivers/pca8574/module.mk
index 825ee9bb7a..c53ed9ab2b 100644
--- a/src/drivers/pca8574/module.mk
+++ b/src/drivers/pca8574/module.mk
@@ -4,3 +4,5 @@
 
 MODULE_COMMAND	 = pca8574
 SRCS		 = pca8574.cpp
+
+MAXOPTIMIZATION	 = -Os