diff --git a/Makefile b/Makefile
index fedc4d56..2cbc7281 100644
--- a/Makefile
+++ b/Makefile
@@ -88,7 +88,7 @@ $(OUT)klipper.o: $(patsubst %.c, $(OUT)src/%.o,$(src-y)) $(OUT)declfunc.lds
 $(OUT)compile_time_request.o: $(OUT)klipper.o ./scripts/buildcommands.py
 	@echo "  Building $@"
 	$(Q)$(OBJCOPY) -j '.compile_time_request' -O binary $< $(OUT)klipper.o.compile_time_request
-	$(Q)$(PYTHON) ./scripts/buildcommands.py $(OUT)klipper.o.compile_time_request $(OUT)autoconf.h $(OUT)compile_time_request.c
+	$(Q)$(PYTHON) ./scripts/buildcommands.py -d $(OUT)klipper.dict $(OUT)klipper.o.compile_time_request $(OUT)autoconf.h $(OUT)compile_time_request.c
 	$(Q)$(CC) $(CFLAGS) -c $(OUT)compile_time_request.c -o $@
 
 $(OUT)klipper.elf: $(OUT)klipper.o $(OUT)compile_time_request.o
diff --git a/scripts/buildcommands.py b/scripts/buildcommands.py
index af9926ca..9b6acb45 100644
--- a/scripts/buildcommands.py
+++ b/scripts/buildcommands.py
@@ -173,7 +173,7 @@ const uint8_t command_identify_data[] PROGMEM = {%s
 // Identify size = %d (%d uncompressed)
 const uint32_t command_identify_size PROGMEM = ARRAY_SIZE(command_identify_data);
 """
-    return fmt % (''.join(out), len(zdata), len(data))
+    return data, fmt % (''.join(out), len(zdata), len(data))
 
 
 ######################################################################
@@ -227,6 +227,8 @@ def main():
     opts = optparse.OptionParser(usage)
     opts.add_option("-e", "--extra", dest="extra", default="",
                     help="extra version string to append to version")
+    opts.add_option("-d", dest="write_dictionary",
+                    help="file to write mcu protocol dictionary")
     opts.add_option("-v", action="store_true", dest="verbose",
                     help="enable debug messages")
 
@@ -302,12 +304,18 @@ def main():
     sys.stdout.write("Version: %s\n" % (version,))
     responses = [msg_to_id[msg] for msgname, msg in messages_by_name.items()
                  if msgname not in commands]
-    icode = build_identify(cmd_by_id, msg_to_id, responses, static_strings
-                           , config, version)
+    datadict, icode = build_identify(cmd_by_id, msg_to_id, responses
+                                     , static_strings, config, version)
     # Write output
     f = open(outcfile, 'wb')
     f.write(FILEHEADER + paramcode + parsercode + cmdcode + icode)
     f.close()
 
+    # Write data dictionary
+    if options.write_dictionary:
+        f = open(options.write_dictionary, 'wb')
+        f.write(datadict)
+        f.close()
+
 if __name__ == '__main__':
     main()