diff --git a/Makefile b/Makefile
index 357262f01..be38d9e08 100644
--- a/Makefile
+++ b/Makefile
@@ -1,4 +1,5 @@
 PYTHON := python
+MD5 := md5sum -c --quiet
 
 .SUFFIXES:
 .SUFFIXES: .asm .o .gbc .png .2bpp .1bpp .lz .pal .bin .blk .tilemap
@@ -56,6 +57,8 @@ crystal: pokecrystal.gbc
 clean:
 	rm -f $(roms) $(all_obj) $(roms:.gbc=.map) $(roms:.gbc=.sym)
 
+compare: pokecrystal.gbc pokecrystal11.gbc
+	@$(MD5) roms.md5
 
 %.asm: ;
 $(all_obj): $$*.asm $$($$*_dep)
diff --git a/roms.md5 b/roms.md5
new file mode 100644
index 000000000..79ca0bc51
--- /dev/null
+++ b/roms.md5
@@ -0,0 +1,2 @@
+9f2922b235a5eeb78d65594e82ef5dde  pokecrystal.gbc
+301899b8087289a6436b0a241fbbb474  pokecrystal11.gbc