1 files changed, 2 insertions, 2 deletions
diff --git a/Common.mk b/Common.mk
index e6e9369..a8bd46a 100644
--- a/Common.mk
+++ b/Common.mk
@@ -81,7 +81,7 @@ else
 endif
 
 ifeq ($(CURRENT_OS),WINDOWS)
-    ifneq ($(shell echo $(ARDUINO_DIR) | egrep '^(/|[a-zA-Z]:\\)'),)
-        echo $(error On Windows, ARDUINO_DIR must be a relative path)
+		ifneq ($(shell echo $(ARDUINO_DIR) | egrep '\\|[[:space:]]|cygdrive'),)
+        echo $(error On Windows, ARDUINO_DIR and other defines must use forward slash and not contain spaces, special characters or be cygdrive relative)
     endif
 endif