diff --git a/local/patches/kf6-kwindowsystem/01-initial-migration.patch b/local/patches/kf6-kwindowsystem/01-initial-migration.patch
new file mode 100644
index 0000000000..436fb791f1
--- /dev/null
+++ b/local/patches/kf6-kwindowsystem/01-initial-migration.patch
@@ -0,0 +1,23 @@
+# Initial migration of the inline sed -i chains in
+# /home/kellito/Builds/RedBear-OS/local/recipes/kde/kf6-kwindowsystem/'s [build].script to a durable external
+# patch. Captured by local/scripts/migrate-kf6-seds-to-patches.sh
+# on 2026-06-12T17:59:03+03:00.
+#
+# After applying this patch via cookbook_apply_patches,
+# the recipe's [build].script should call:
+#     REDBEAR_PATCHES_DIR="/home/kellito/Builds/RedBear-OS/local/patches/kf6-kwindowsystem"
+#     cookbook_apply_patches "${REDBEAR_PATCHES_DIR}"
+# in place of the sed -i chains that produced these edits.
+
+diff -ruN '--exclude=.git' '--exclude=target' '--exclude=.clang-format' '--exclude=.gitignore' /home/kellito/Builds/RedBear-OS/local/recipes/kde/kf6-kwindowsystem//source-pristine/CMakeLists.txt /home/kellito/Builds/RedBear-OS/local/recipes/kde/kf6-kwindowsystem//source/CMakeLists.txt
+--- /home/kellito/Builds/RedBear-OS/local/recipes/kde/kf6-kwindowsystem//source-pristine/CMakeLists.txt	2026-06-12 17:58:14.097649577 +0300
++++ /home/kellito/Builds/RedBear-OS/local/recipes/kde/kf6-kwindowsystem//source/CMakeLists.txt	2026-06-12 17:58:56.877257856 +0300
+@@ -86,7 +86,7 @@
+ set(KWINDOWSYSTEM_HAVE_X11 ${KWINDOWSYSTEM_X11})
+ 
+ # Subdirectories
+-ecm_install_po_files_as_qm(poqm)
++#ecm_install_po_files_as_qm(poqm)
+ 
+ ecm_set_disabled_deprecation_versions(
+     QT 6.11.0
diff --git a/local/scripts/migrate-kf6-seds-to-patches.sh b/local/scripts/migrate-kf6-seds-to-patches.sh
index 5558b15dfd..bce2833ebb 100755
--- a/local/scripts/migrate-kf6-seds-to-patches.sh
+++ b/local/scripts/migrate-kf6-seds-to-patches.sh
@@ -179,8 +179,16 @@ for recipe_dir in "${recipe_dirs[@]}"; do
     timeout 600 ./target/release/repo cook "$name" >>"$log_file" 2>&1 || true
 
     # Step 4: diff pristine vs post-cook.
+    #
+    # Exclude ECM-generated files that the cmake configure step
+    # creates on every run: `.clang-format` (clang-format style
+    # config), `.gitignore` (gitignore rules for the build dir),
+    # and any `target/` build outputs. These are NOT Red Bear
+    # edits and would pollute the patch with autogenerated noise.
     diff_out=$(diff -ruN "$pristine_dir" "$recipe_dir/source" \
-        --exclude='.git' --exclude='target' 2>/dev/null || true)
+        --exclude='.git' --exclude='target' \
+        --exclude='.clang-format' --exclude='.gitignore' \
+        2>/dev/null || true)
     if [ -z "$diff_out" ]; then
         echo "  NOTE: cook produced no diff (sed chains may have been no-ops)"
         rm -rf "$pristine_dir"
diff --git a/local/scripts/tests/test_migrate_kf6_seds.py b/local/scripts/tests/test_migrate_kf6_seds.py
index eb51db86a7..54d27821a2 100644
--- a/local/scripts/tests/test_migrate_kf6_seds.py
+++ b/local/scripts/tests/test_migrate_kf6_seds.py
@@ -219,6 +219,25 @@ class TestScriptStructure(unittest.TestCase):
             "cook call must be wrapped in `timeout N`",
         )
 
+    def test_diff_excludes_ecm_generated_files(self):
+        # ECM (Extra CMake Modules) writes a `.clang-format`
+        # config file and a `.gitignore` file during the cmake
+        # configure step on every cook. These are NOT Red Bear
+        # edits and would pollute the migration patch with
+        # autogenerated noise (95+ lines for `.clang-format`
+        # alone). The diff must exclude them.
+        text = SCRIPT.read_text()
+        self.assertIn(
+            ".clang-format",
+            text,
+            "diff command must exclude .clang-format (ECM autogenerated)",
+        )
+        self.assertIn(
+            ".gitignore",
+            text,
+            "diff command must exclude .gitignore (ECM autogenerated)",
+        )
+
 
 if __name__ == "__main__":
     unittest.main()