diff --git a/sim/m32c/Makefile.in b/sim/m32c/Makefile.in
index c5b1495c705..c88b387bf84 100644
--- a/sim/m32c/Makefile.in
+++ b/sim/m32c/Makefile.in
@@ -20,7 +20,7 @@
 
 ## COMMON_PRE_CONFIG_FRAG
 
-SIM_EXTRA_CFLAGS = -Wall -DTIMER_A
+SIM_EXTRA_CFLAGS = -DTIMER_A
 
 SIM_RUN_OBJS = \
 	main.o \
diff --git a/sim/rl78/Makefile.in b/sim/rl78/Makefile.in
index 257bad04960..2dae7df682e 100644
--- a/sim/rl78/Makefile.in
+++ b/sim/rl78/Makefile.in
@@ -20,8 +20,6 @@
 
 ## COMMON_PRE_CONFIG_FRAG
 
-SIM_EXTRA_CFLAGS = -Wall
-
 SIM_RUN_OBJS = \
 	main.o