diff --git a/examples/lm3s/Makefile.include b/examples/lm3s/Makefile.include
index f5190638..c9bd33ca 100644
--- a/examples/lm3s/Makefile.include
+++ b/examples/lm3s/Makefile.include
@@ -37,7 +37,7 @@ endif
 endif
 
 CFLAGS		+= -O0 -g3 -Wall -Wextra -I$(TOOLCHAIN_DIR)/include -fno-common \
-		   -mcpu=cortex-m3 -mthumb -MD
+		   -mcpu=cortex-m3 -mthumb -MD -DLM3S
 LDSCRIPT	?= $(BINARY).ld
 LDFLAGS         += -L$(TOOLCHAIN_DIR)/lib \
 		   -T$(LDSCRIPT) -nostartfiles -Wl,--gc-sections
diff --git a/examples/lpc13xx/Makefile.include b/examples/lpc13xx/Makefile.include
index d8aeff09..0b220638 100644
--- a/examples/lpc13xx/Makefile.include
+++ b/examples/lpc13xx/Makefile.include
@@ -37,7 +37,7 @@ endif
 endif
 
 CFLAGS		+= -Os -g -Wall -Wextra -I$(TOOLCHAIN_DIR)/include -fno-common \
-		   -mcpu=cortex-m3 -mthumb -MD
+		   -mcpu=cortex-m3 -mthumb -MD -DLPC13XX
 LDSCRIPT	?= $(BINARY).ld
 LDFLAGS         += -L$(TOOLCHAIN_DIR)/lib \
 		   -T$(LDSCRIPT) -nostartfiles -Wl,--gc-sections
diff --git a/examples/lpc17xx/Makefile.include b/examples/lpc17xx/Makefile.include
index 6d7bbfe5..9c38a68d 100644
--- a/examples/lpc17xx/Makefile.include
+++ b/examples/lpc17xx/Makefile.include
@@ -37,7 +37,7 @@ endif
 endif
 
 CFLAGS		+= -O0 -g -Wall -Wextra -I$(TOOLCHAIN_DIR)/include -fno-common \
-		   -mcpu=cortex-m3 -mthumb -MD
+		   -mcpu=cortex-m3 -mthumb -MD -DLPC17XX
 LDSCRIPT	?= $(BINARY).ld
 LDFLAGS         += -L$(TOOLCHAIN_DIR)/lib \
 		   -T$(LDSCRIPT) -nostartfiles -Wl,--gc-sections
diff --git a/examples/lpc43xx/Makefile.include b/examples/lpc43xx/Makefile.include
index 15e523b4..cf78538f 100644
--- a/examples/lpc43xx/Makefile.include
+++ b/examples/lpc43xx/Makefile.include
@@ -41,7 +41,7 @@ endif
 
 CFLAGS		+= -O2 -g -Wall -Wextra -I$(TOOLCHAIN_DIR)/include -fno-common \
 		   -mcpu=cortex-m4 -mthumb -MD \
-		   -mfloat-abi=hard -mfpu=fpv4-sp-d16
+		   -mfloat-abi=hard -mfpu=fpv4-sp-d16 -DLPC43XX
 LDSCRIPT	?= $(BINARY).ld
 LDFLAGS         += -L$(TOOLCHAIN_DIR)/lib \
 		   -T$(LDSCRIPT) -nostartfiles -Wl,--gc-sections -Xlinker -Map=$(BINARY).map
diff --git a/lib/lm3s/Makefile b/lib/lm3s/Makefile
index e471a001..6fc814d4 100644
--- a/lib/lm3s/Makefile
+++ b/lib/lm3s/Makefile
@@ -25,7 +25,7 @@ CC		= $(PREFIX)-gcc
 AR		= $(PREFIX)-ar
 CFLAGS		= -Os -g -Wall -Wextra -I../../include -fno-common \
 		  -mcpu=cortex-m3 -mthumb -Wstrict-prototypes \
-		  -ffunction-sections -fdata-sections -MD
+		  -ffunction-sections -fdata-sections -MD -DLM3S
 # ARFLAGS	= rcsv
 ARFLAGS		= rcs
 OBJS		= gpio.o vector.o assert.o
diff --git a/lib/lpc13xx/Makefile b/lib/lpc13xx/Makefile
index dd460b8f..15bc6868 100644
--- a/lib/lpc13xx/Makefile
+++ b/lib/lpc13xx/Makefile
@@ -25,7 +25,7 @@ CC		= $(PREFIX)-gcc
 AR		= $(PREFIX)-ar
 CFLAGS		= -Os -g -Wall -Wextra -I../../include -fno-common \
 		  -mcpu=cortex-m3 -mthumb -Wstrict-prototypes \
-		  -ffunction-sections -fdata-sections -MD
+		  -ffunction-sections -fdata-sections -MD -DLPC13XX
 # ARFLAGS	= rcsv
 ARFLAGS		= rcs
 OBJS		= gpio.o
diff --git a/lib/lpc17xx/Makefile b/lib/lpc17xx/Makefile
index f5fa7927..19fc1529 100644
--- a/lib/lpc17xx/Makefile
+++ b/lib/lpc17xx/Makefile
@@ -25,7 +25,7 @@ CC		= $(PREFIX)-gcc
 AR		= $(PREFIX)-ar
 CFLAGS		= -O0 -g -Wall -Wextra -I../../include -fno-common \
 		  -mcpu=cortex-m3 -mthumb -Wstrict-prototypes \
-		  -ffunction-sections -fdata-sections -MD
+		  -ffunction-sections -fdata-sections -MD -DLPC17XX
 # ARFLAGS	= rcsv
 ARFLAGS		= rcs
 OBJS		= gpio.o
diff --git a/lib/lpc43xx/Makefile b/lib/lpc43xx/Makefile
index a3a5361f..efbba0dd 100644
--- a/lib/lpc43xx/Makefile
+++ b/lib/lpc43xx/Makefile
@@ -28,7 +28,7 @@ AR		= $(PREFIX)-ar
 CFLAGS		= -O2 -g3 -Wall -Wextra -I../../include -fno-common \
 		  -mcpu=cortex-m4 -mthumb -Wstrict-prototypes \
 		  -ffunction-sections -fdata-sections -MD \
-		  -mfloat-abi=hard -mfpu=fpv4-sp-d16
+		  -mfloat-abi=hard -mfpu=fpv4-sp-d16 -DLPC43XX
 # ARFLAGS	= rcsv
 ARFLAGS		= rcs
 OBJS		= gpio.o scu.o i2c.o ssp.o