diff --git a/.github/workflows/validate-config.yml b/.github/workflows/validate-config.yml
index c99bcbd..9ebc696 100644
--- a/.github/workflows/validate-config.yml
+++ b/.github/workflows/validate-config.yml
@@ -7,13 +7,18 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v2
+      - uses: actions/checkout@v2
 
-    - name: BOM check
-      run: |
-        ! grep -rlI $'\xEF\xBB\xBF' ispdb
+      - name: BOM check
+        run: |
+          ! grep -rlI $'\xEF\xBB\xBF' ispdb
 
-    - name: Validate file extensions
-      run: | 
-       set -o pipefail
-       ls -1 ispdb/ | grep -v '\.xml$' | awk '{print "::error file=ispdb/"$0"::File name \"ispdb/"$0"\" does not end in .xml – Please rename!"}' && exit 1 || true
+      - name: Validate file extensions
+        run: |
+          set -o pipefail
+          ls -1 ispdb/ | grep -v '\.xml$' | awk '{print "::error file=ispdb/"$0"::File name \"ispdb/"$0"\" does not end in .xml – Please rename!"}' && exit 1 || true
+
+      - name: Validate XML content
+        run: |
+          pip install lxml
+          python tools/validate.py ispdb/*
diff --git a/ispdb/naver.com.xml b/ispdb/naver.com.xml
index bd11fcf..78a4fa9 100644
--- a/ispdb/naver.com.xml
+++ b/ispdb/naver.com.xml
@@ -25,6 +25,6 @@
       <username>%EMAILADDRESS%</username>
       <authentication>password-encrypted</authentication>
     </outgoingServer>
-    <documentation url="https://help.naver.com/service/30029/contents/21342?osType=PC&amp;lang=ko"/>
+    <documentation url="https://help.naver.com/service/30029/contents/21342?osType=PC&amp;lang=ko" />
   </emailProvider>
-</clientConfig>
+</clientConfig>
\ No newline at end of file
diff --git a/tools/validate.py b/tools/validate.py
new file mode 100644
index 0000000..9604470
--- /dev/null
+++ b/tools/validate.py
@@ -0,0 +1,51 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# This script checks all input files to validate that their content is valid
+# XML. It is meant to run in the CI for PRs against the autoconfig repository.
+
+import argparse
+import os
+import sys
+from typing import List
+from lxml import etree
+
+
+def main():
+    parser = argparse.ArgumentParser()
+    parser.add_argument(
+        "file", nargs="*", help="input file(s) to process, wildcards allowed"
+    )
+    args = parser.parse_args(sys.argv[1:])
+
+    # Defining `files` here isn't strictly necessary, but the extra typing
+    # (which we can't really get otherwise) helps with maintenance.
+    files: List[str] = args.file
+
+    # The exit code. Stays 0 unless we encounter a file that doesn't parse.
+    ret = 0
+
+    for f in files:
+        # Filter out directories an non-XML files
+        if os.path.isdir(f):
+            print(f"Ignoring directory {f}")
+            continue
+
+        if not f.endswith(".xml"):
+            print(f"Ignoring non-XML file {f}")
+            continue
+
+        # Try parsing the file. If this did not work, print the error and set
+        # the exit code to 1.
+        try:
+            etree.parse(f)
+        except Exception as e:
+            print(f"File {f} did not parse: {e}")
+            ret = 1
+
+    exit(ret)
+
+
+if __name__ == "__main__":
+    main()