diff --git a/qemu-arm/Makefile b/qemu-arm/Makefile
index 03cc7db9e0d62c9c2a6dd65a7ae876ae871e9a4c..9005380809455ef3c0e02ee4571dc8f34f85ff5b 100644
--- a/qemu-arm/Makefile
+++ b/qemu-arm/Makefile
@@ -14,7 +14,7 @@ INC += -I$(PY_SRC)
 INC += -I$(BUILD)
 
 CFLAGS_CORTEX_M3 = -mthumb -mcpu=cortex-m3
-CFLAGS = $(INC) -Wall -Werror -ansi -std=gnu99 $(CFLAGS_CORTEX_M3) $(COPT) \
+CFLAGS = $(INC) -Wall -Wpointer-arith -Werror -ansi -std=gnu99 $(CFLAGS_CORTEX_M3) $(COPT) \
 	 -flto -ffunction-sections -fdata-sections
 
 #Debugging/Optimization
diff --git a/stmhal/Makefile b/stmhal/Makefile
index 878e6ca10b342fe816b3d1fefeacc1ffa0255684..f444f00458b7639586bd19bfb847809f7d7923db 100644
--- a/stmhal/Makefile
+++ b/stmhal/Makefile
@@ -42,7 +42,7 @@ INC += -I$(USBDEV_DIR)/core/inc -I$(USBDEV_DIR)/class/cdc_msc_hid/inc
 INC += -I$(FATFS_DIR)/src
 
 CFLAGS_CORTEX_M4 = -mthumb -mtune=cortex-m4 -mabi=aapcs-linux -mcpu=cortex-m4 -mfpu=fpv4-sp-d16 -mfloat-abi=hard -fsingle-precision-constant -Wdouble-promotion
-CFLAGS = $(INC) -Wall -Werror -ansi -std=gnu99 -nostdlib $(CFLAGS_MOD) $(CFLAGS_CORTEX_M4) $(COPT)
+CFLAGS = $(INC) -Wall -Wpointer-arith -Werror -ansi -std=gnu99 -nostdlib $(CFLAGS_MOD) $(CFLAGS_CORTEX_M4) $(COPT)
 CFLAGS += -Iboards/$(BOARD)
 
 LDFLAGS = -nostdlib -T stm32f405.ld -Map=$(@:.elf=.map) --cref
diff --git a/teensy/Makefile b/teensy/Makefile
index 5746f6c432aeb557442a870475ec372a01ef226a..5ea4c9dad226f6505f293caa751c4594632d02eb 100644
--- a/teensy/Makefile
+++ b/teensy/Makefile
@@ -35,7 +35,7 @@ INC += -I../stmhal
 INC += -I$(BUILD)
 INC += -Icore
 
-CFLAGS = $(INC) -Wall -ansi -std=gnu99 -nostdlib $(CFLAGS_CORTEX_M4)
+CFLAGS = $(INC) -Wall -Wpointer-arith -ansi -std=gnu99 -nostdlib $(CFLAGS_CORTEX_M4)
 LDFLAGS = -nostdlib -T mk20dx256.ld -msoft-float -mfloat-abi=soft
 
 ifeq ($(USE_ARDUINO_TOOLCHAIN),1)
diff --git a/unix-cpy/Makefile b/unix-cpy/Makefile
index 0376932d6a012e0d5323790a10ff54ce5ed76d2f..eb4088861c58d8292d95a7611d661369e945fbbc 100644
--- a/unix-cpy/Makefile
+++ b/unix-cpy/Makefile
@@ -11,7 +11,7 @@ INC += -I$(PY_SRC)
 INC += -I$(BUILD)
 
 # compiler settings
-CFLAGS = $(INC) -Wall -Werror -ansi -std=gnu99 -DUNIX
+CFLAGS = $(INC) -Wall -Wpointer-arith -Werror -ansi -std=gnu99 -DUNIX
 LDFLAGS = -lm
 
 # Debugging/Optimization
diff --git a/unix/Makefile b/unix/Makefile
index 8ee2319828ac72e8f479f83f998f8e15e6052726..d8b51d0b0fb7ef237e0ca9ee6a4fc95be3550490 100644
--- a/unix/Makefile
+++ b/unix/Makefile
@@ -18,7 +18,7 @@ INC += -I$(PY_SRC)
 INC += -I$(BUILD)
 
 # compiler settings
-CWARN = -Wall -Werror
+CWARN = -Wall -Wpointer-arith -Werror
 CFLAGS = $(INC) $(CWARN) -ansi -std=gnu99 -DUNIX $(CFLAGS_MOD) $(COPT) $(CFLAGS_EXTRA)
 
 # Debugging/Optimization
diff --git a/windows/Makefile b/windows/Makefile
index 44029c028f3724ee16b7e81146f83dcba283f9ad..d83a5d46f6aa30a4fb05b7eefd3a60a79ee6654b 100644
--- a/windows/Makefile
+++ b/windows/Makefile
@@ -15,7 +15,7 @@ INC += -I$(PY_SRC)
 INC += -I$(BUILD)
 
 # compiler settings
-CFLAGS = $(INC) -Wall -Werror -ansi -std=gnu99 -DUNIX $(CFLAGS_MOD) $(COPT)
+CFLAGS = $(INC) -Wall -Wpointer-arith -Werror -ansi -std=gnu99 -DUNIX $(CFLAGS_MOD) $(COPT)
 LDFLAGS = $(LDFLAGS_MOD) -lm
 ifeq ($(CROSS_COMPILE),i686-w64-mingw32-)
 CFLAGS += -D__USE_MINGW_ANSI_STDIO=1