diff --git a/Makefile b/Makefile
index f5f4bd8..8b0e7b3 100644
--- a/Makefile
+++ b/Makefile
@@ -2,7 +2,7 @@
 
 # Detect the operating system and architecture.
 
-include makefiles/osdetect.Makefile
+include makefiles/osdetect.mk
 
 # -----------------------------------------------------------------------------
 # Variables
@@ -52,8 +52,8 @@ default: help
 # Operating System / Architecture targets
 # -----------------------------------------------------------------------------
 
--include makefiles/$(OSTYPE).Makefile
--include makefiles/$(OSTYPE)_$(OSARCH).Makefile
+-include makefiles/$(OSTYPE).mk
+-include makefiles/$(OSTYPE)_$(OSARCH).mk
 
 
 .PHONY: hello-world
diff --git a/makefiles/darwin.Makefile b/makefiles/darwin.mk
similarity index 100%
rename from makefiles/darwin.Makefile
rename to makefiles/darwin.mk
diff --git a/makefiles/linux.Makefile b/makefiles/linux.mk
similarity index 100%
rename from makefiles/linux.Makefile
rename to makefiles/linux.mk
diff --git a/makefiles/osdetect.Makefile b/makefiles/osdetect.mk
similarity index 100%
rename from makefiles/osdetect.Makefile
rename to makefiles/osdetect.mk
diff --git a/makefiles/windows.Makefile b/makefiles/windows.mk
similarity index 100%
rename from makefiles/windows.Makefile
rename to makefiles/windows.mk