Update Makefile
diff --git a/Makefile b/Makefile
index 7ba14ad..3b25487 100644
--- a/Makefile
+++ b/Makefile
@@ -68,7 +68,7 @@
 
 ifeq ($(PDK),gf180mcuC)
 
-	MPW_TAG ?= gfmpw-0a
+	MPW_TAG ?= gfmpw-0b
 	CARAVEL_NAME := caravel
 	CARAVEL_REPO := https://github.com/efabless/caravel-gf180mcu
 	CARAVEL_TAG := $(MPW_TAG)