diff --git a/core/main.mk b/core/main.mk
index ab49415..74424ee 100644
--- a/core/main.mk
+++ b/core/main.mk
@@ -12,6 +12,13 @@
 # this turns off the suffix rules built into make
 .SUFFIXES:
 
+# this turns off the RCS / SCCS implicit rules of GNU Make
+% : RCS/%,v
+% : RCS/%
+% : %,v
+% : s.%
+% : SCCS/s.%
+
 # If a rule fails, delete $@.
 .DELETE_ON_ERROR:
 
@@ -434,7 +441,7 @@
 else	# !SDK_ONLY
 ifeq ($(BUILD_TINY_ANDROID), true)
 
-# TINY_ANDROID is a super-minimal build configuration, handy for board 
+# TINY_ANDROID is a super-minimal build configuration, handy for board
 # bringup and very low level debugging
 
 subdirs := \