diff --git a/HISTORY.md b/HISTORY.md
index d52d981..f075ede 100644
--- a/HISTORY.md
+++ b/HISTORY.md
@@ -18,7 +18,8 @@ I tried to give credit whenever possible. If I have missed anyone, kindly add it
 - Tweak: Don't append port details to avrdude for usbtiny. Fix #140 and #138 (https://github.com/PPvG)
 - Fix: Handle relative paths of bootloader file while burning bootloaders. Fix #126 and #142 (https://github.com/sej7278)
 - New: Add `CONTRIBUTING.md` explaining how to contribute to the project.
-- Force -Os optimization for SoftwareSerial. Add `OPTIMIZATION_FLAGS` and `DEBUG_FLAGS`.
+- New: Force -Os optimization for SoftwareSerial. Add `OPTIMIZATION_FLAGS` and `DEBUG_FLAGS`. (https://github.com/mahoy)
+- Fix: Use `ARDUINO_HEADER` variable instead of hardcoded file names. Fix #131 
 
 ### 1.0.1 (2013-09-25)
 - Unconditionally add -D in avrdude options. See #114
diff --git a/arduino-mk/Arduino.mk b/arduino-mk/Arduino.mk
index 5ee2fdb..2d76275 100644
--- a/arduino-mk/Arduino.mk
+++ b/arduino-mk/Arduino.mk
@@ -703,11 +703,11 @@ ifeq ($(strip $(NO_CORE)),)
 endif
 
 ########################################################################
-# Include file to use for old .pde files
+# Include Arduino Header file
 
 ifndef ARDUINO_HEADER
-    # We should check for Arduino version, if the file is .pde because a
-    # .pde file might be used in Arduino 1.0
+    # We should check for Arduino version, not just the file extension
+    # because, a .pde file can be used in Arduino 1.0 as well
     ifeq ($(shell expr $(ARDUINO_VERSION) '<' 100), 1)
         ARDUINO_HEADER=WProgram.h
     else
@@ -931,7 +931,7 @@ $(OBJDIR)/%.o: %.pde $(COMMON_DEPS) | $(OBJDIR)
 # the ino -> o file
 $(OBJDIR)/%.o: %.ino $(COMMON_DEPS) | $(OBJDIR)
 	@$(MKDIR) $(dir $@)
-	$(CXX) -x c++ -include Arduino.h -MMD -c $(CPPFLAGS) $(CXXFLAGS) $< -o $@
+	$(CXX) -x c++ -include $(ARDUINO_HEADER) -MMD -c $(CPPFLAGS) $(CXXFLAGS) $< -o $@
 
 # generated assembly
 $(OBJDIR)/%.s: %.pde $(COMMON_DEPS) | $(OBJDIR)
@@ -940,7 +940,7 @@ $(OBJDIR)/%.s: %.pde $(COMMON_DEPS) | $(OBJDIR)
 
 $(OBJDIR)/%.s: %.ino $(COMMON_DEPS) | $(OBJDIR)
 	@$(MKDIR) $(dir $@)
-	$(CXX) -x c++ -include Arduino.h -MMD -S -fverbose-asm $(CPPFLAGS) $(CXXFLAGS) $< -o $@
+	$(CXX) -x c++ -include $(ARDUINO_HEADER) -MMD -S -fverbose-asm $(CPPFLAGS) $(CXXFLAGS) $< -o $@
 
 #$(OBJDIR)/%.lst: $(OBJDIR)/%.s
 #	$(AS) -$(MCU_FLAG_NAME)=$(MCU) -alhnd $< > $@