diff --git a/BuildTests/BoardDriverTest/makefile b/BuildTests/BoardDriverTest/makefile
index de49759a74ee24a4d3057e39ce8d7ae67af50ea1..3bbfaece130c0df93378515b1d83de68fd895ab4 100644
--- a/BuildTests/BoardDriverTest/makefile
+++ b/BuildTests/BoardDriverTest/makefile
@@ -12,7 +12,7 @@
 # compiler.
 
 # Path to the LUFA library core
-LUFA_PATH         = ../../LUFA/
+LUFA_PATH := ../../LUFA/
 
 
 all: begin makeboardlist testboards clean end
diff --git a/BuildTests/BootloaderTest/makefile b/BuildTests/BootloaderTest/makefile
index 1294ba0841edcd1872a45c4cfaf8abf5aabf4783..e894e6f79fd196bcf3b5d0e18247cc03be2031aa 100644
--- a/BuildTests/BootloaderTest/makefile
+++ b/BuildTests/BootloaderTest/makefile
@@ -11,7 +11,7 @@
 # with all supported device configurations.
 
 # Path to the LUFA library core
-LUFA_PATH         = ../../LUFA/
+LUFA_PATH := ../../LUFA/
 
 
 all: begin testbootloaders clean end
diff --git a/BuildTests/ModuleTest/makefile b/BuildTests/ModuleTest/makefile
index b997b35132cb55b53ba32cba78f7ff58cb6b0d3a..1d243ddc69c0a997ee3565be96254d9b55b555e8 100644
--- a/BuildTests/ModuleTest/makefile
+++ b/BuildTests/ModuleTest/makefile
@@ -13,15 +13,15 @@
 # application.
 
 # Path to the LUFA library core
-LUFA_PATH         = ../../LUFA/
+LUFA_PATH := ../../LUFA/
 
 # List of device families per architecture, one device per architecture sub-family
-AVR8_FAMILIES  = at90usb1287 at90usb1286 atmega16u4 atmega16u2 at90usb162
-XMEGA_FAMILIES = atxmega128a1u atxmega128a3u atxmega256a3bu atxmega128a4u atxmega128b1 atxmega128b3 atxmega128c3 atxmega32c4
-UC3_FAMILIES   = uc3a0256 uc3a1256 uc3a3256 uc3a4256 uc3b0256 uc3b1256
+AVR8_FAMILIES   := at90usb1287 at90usb1286 atmega16u4 atmega16u2 at90usb162
+XMEGA_FAMILIES  := atxmega128a1u atxmega128a3u atxmega256a3bu atxmega128a4u atxmega128b1 atxmega128b3 atxmega128c3 atxmega32c4
+UC3_FAMILIES    := uc3a0256 uc3a1256 uc3a3256 uc3a4256 uc3b0256 uc3b1256
 
 # List of all device families, with a family postfix
-DEVICE_FAMILIES = $(AVR8_FAMILIES:%=%.avr8) $(XMEGA_FAMILIES:%=%.xmega) $(UC3_FAMILIES:%=%.uc3)
+DEVICE_FAMILIES := $(AVR8_FAMILIES:%=%.avr8) $(XMEGA_FAMILIES:%=%.xmega) $(UC3_FAMILIES:%=%.uc3)
 
 
 all: begin $(DEVICE_FAMILIES) clean end
diff --git a/BuildTests/SingleUSBModeTest/makefile b/BuildTests/SingleUSBModeTest/makefile
index d5fd3f06e67625dc4d991e30ba62ad215a688608..14667474cf9819b99287467ae4594a41ec5389f0 100644
--- a/BuildTests/SingleUSBModeTest/makefile
+++ b/BuildTests/SingleUSBModeTest/makefile
@@ -12,7 +12,7 @@
 # all supported architectures
 
 # Path to the LUFA library core
-LUFA_PATH         = ../../LUFA/
+LUFA_PATH := ../../LUFA/
 
 all: begin compile clean end
 
diff --git a/BuildTests/StaticAnalysisTest/makefile b/BuildTests/StaticAnalysisTest/makefile
index 6562a963611893a23c11891f22b15405d0f83d89..a2626ec29c448c6a00eb96bcf24257c6405b8a08 100644
--- a/BuildTests/StaticAnalysisTest/makefile
+++ b/BuildTests/StaticAnalysisTest/makefile
@@ -9,15 +9,15 @@
 # Static anlysis of the entire LUFA source tree, using the free cross-platform "cppcheck" tool.
 
 # Path to the LUFA library core
-LUFA_PATH         = ../../LUFA/
+LUFA_PATH := ../../LUFA/
 
-CPPCHECK_EXCLUDES = FATFs/            \
-                    PetiteFATFs/      \
-                    uip/
-CPPCHECK_INCLUDES = $(patsubst %/,%,$(LUFA_PATH))/CodeTemplates/   \
-                    $(patsubst %/,%,$(LUFA_PATH))/../Projects/AVRISP-MKII/
+CPPCHECK_EXCLUDES := FATFs/            \
+                     PetiteFATFs/      \
+                     uip/
+CPPCHECK_INCLUDES := $(patsubst %/,%,$(LUFA_PATH))/CodeTemplates/               \
+                     $(patsubst %/,%,$(LUFA_PATH))/../Projects/AVRISP-MKII/
 
-SRC               = $(patsubst %/,%,$(LUFA_PATH))/..
+SRC               := $(patsubst %/,%,$(LUFA_PATH))/..
 
 all: begin cppcheck-config cppcheck end
 
diff --git a/Maintenance/makefile b/Maintenance/makefile
index f158381789c8a6c4d4a46a4ae048d890263cf163..e72ae604ae4cae4bc17ca148dd4fcf5fde3b47fe 100644
--- a/Maintenance/makefile
+++ b/Maintenance/makefile
@@ -10,7 +10,7 @@
 
 
 # Path to the root of the LUFA tree
-LUFA_ROOT = ../
+LUFA_ROOT := ../
 
 all: