diff --git a/BuildTests/BoardDriverTest/makefile b/BuildTests/BoardDriverTest/makefile
index f039a3a7d53388e704cdbdccfd46733d1a02f138..11847511e7f8e828ef298a227c175f1326fc4321 100644
--- a/BuildTests/BoardDriverTest/makefile
+++ b/BuildTests/BoardDriverTest/makefile
@@ -14,6 +14,8 @@
 # Path to the LUFA library core
 LUFA_PATH := ../../LUFA/
 
+# Build test cannot be run with multiple parallel jobs
+.NOTPARALLEL:
 
 all: begin makeboardlist testboards clean end
 
diff --git a/BuildTests/BootloaderTest/makefile b/BuildTests/BootloaderTest/makefile
index d15a85e4bfe67cf7ad64cc2ebac01cbc5304f4b2..d73bbf3aac1aea1fc53a970d526b18f6de0d20a0 100644
--- a/BuildTests/BootloaderTest/makefile
+++ b/BuildTests/BootloaderTest/makefile
@@ -13,6 +13,8 @@
 # Path to the LUFA library core
 LUFA_PATH := ../../LUFA/
 
+# Build test cannot be run with multiple parallel jobs
+.NOTPARALLEL:
 
 all: begin testbootloaders clean end
 
diff --git a/BuildTests/ModuleTest/makefile b/BuildTests/ModuleTest/makefile
index 196fc32b21ecfbe51de184f3477c889f20ea0b97..39baf283b4e992aef52f15729adb2d6cbcd634c3 100644
--- a/BuildTests/ModuleTest/makefile
+++ b/BuildTests/ModuleTest/makefile
@@ -15,6 +15,9 @@
 # Path to the LUFA library core
 LUFA_PATH := ../../LUFA/
 
+# Build test cannot be run with multiple parallel jobs
+.NOTPARALLEL:
+
 # 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
diff --git a/BuildTests/SingleUSBModeTest/makefile b/BuildTests/SingleUSBModeTest/makefile
index 7b5b06040da8eb3ca3cdc51196f5ab550b14d663..d31f5f02802e8e7a2191aee9641b0eccefa2e5f3 100644
--- a/BuildTests/SingleUSBModeTest/makefile
+++ b/BuildTests/SingleUSBModeTest/makefile
@@ -14,6 +14,9 @@
 # Path to the LUFA library core
 LUFA_PATH := ../../LUFA/
 
+# Build test cannot be run with multiple parallel jobs
+.NOTPARALLEL:
+
 all: begin compile clean end
 
 begin: