diff --git a/.travis.yml b/.travis.yml
index e5fc5ded713..5850e557ac2 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -32,6 +32,7 @@ jobs:
         - find . -name "*.json" -not -path "*/node_modules/*" -print0 | xargs -0 python3 ./tools/json_verifier.py
         - tools/travis/build_tgui.sh
         - tools/travis/check_grep.sh
+        - python3 -m pip install -r tools/mapmerge2/requirements.txt && python3 tools/mapmerge2/dmi.py --test
         - ~/dreamchecker
 
     - name: "Compile All Maps"
diff --git a/tools/mapmerge2/dmi.py b/tools/mapmerge2/dmi.py
index 7e1c75cf8d5..e87cf507b99 100644
--- a/tools/mapmerge2/dmi.py
+++ b/tools/mapmerge2/dmi.py
@@ -217,7 +217,8 @@ class State:
         return self.frames[self._frame_index(*args, **kwargs)]
 
 def escape(text):
-    assert '\\' not in text and '"' not in text
+    text = text.replace('\\', '\\\\')
+    text = text.replace('"', '\\"')
     return f'"{text}"'
 
 def unescape(text, quote='"'):
@@ -226,7 +227,8 @@ def unescape(text, quote='"'):
     if not (text.startswith(quote) and text.endswith(quote)):
         raise ValueError(text)
     text = text[1:-1]
-    assert '\\' not in text and quote not in text
+    text = text.replace('\\"', '"')
+    text = text.replace('\\\\', '\\')
     return text
 
 def parse_num(value):
@@ -239,7 +241,7 @@ def parse_bool(value):
         raise ValueError(value)
     return value == '1'
 
-if __name__ == '__main__':
+def _self_test():
     # test: can we load every DMI in the tree
     import os
 
@@ -249,7 +251,31 @@ if __name__ == '__main__':
             dirnames.remove('.git')
         for filename in filenames:
             if filename.endswith('.dmi'):
-                Dmi.from_file(os.path.join(dirpath, filename))
+                fullpath = os.path.join(dirpath, filename)
+                try:
+                    Dmi.from_file(fullpath)
+                except:
+                    print('Failed on:', fullpath)
+                    raise
                 count += 1
 
     print(f"Successfully parsed {count} dmi files")
+
+def _usage():
+    import sys
+    print(f"Usage:")
+    print(f"    {sys.argv[0]} --test")
+    exit(1)
+
+def _main():
+    import sys
+    if len(sys.argv) < 2:
+        return _usage()
+
+    if sys.argv[1] == '--test':
+        return _self_test()
+
+    return _usage()
+
+if __name__ == '__main__':
+    _main()