diff --git a/Makefile b/Makefile
index b016433..2b250b3 100644
--- a/Makefile
+++ b/Makefile
@@ -1,4 +1,4 @@
-.PHONY: build clean validate test all schemas schema-validate
+.PHONY: build clean validate test all schemas schema-validate lint
 
 DIST := dist
 SRC := src
@@ -21,6 +21,12 @@ endif
 	uv run x4cat extract "$(X4_GAME_DIR)" -o $(SCHEMAS) -g '*.xsd'
 	@echo "Schemas extracted to $(SCHEMAS)/"
 
+lint:
+ifndef X4_GAME_DIR
+	$(error X4_GAME_DIR not set — e.g. make lint X4_GAME_DIR="/path/to/X4 Foundations")
+endif
+	uv run x4cat validate-diff "$(X4_GAME_DIR)" $(SRC)
+
 schema-validate:
 	uv run pytest tests/test_mod.py::TestSchema -q
 
diff --git a/README.md b/README.md
index 6adf635..6661355 100644
--- a/README.md
+++ b/README.md
@@ -35,6 +35,18 @@ make test             # full test suite (includes build verification)
 make clean            # remove dist/
 ```
 
+## Diff patch linting
+
+Validate that all XML diff patches in `src/` have XPath selectors that match
+the base game files they target:
+
+```bash
+make lint X4_GAME_DIR="/path/to/X4 Foundations"
+```
+
+Reports mismatches with file path, line number, and the failing XPath.
+Skipped gracefully when no diff patches exist in `src/`.
+
 ## Schema validation
 
 Optionally extract XSD schemas from your X4 install for full schema validation
diff --git a/uv.lock b/uv.lock
index edc620d..5f48264 100644
--- a/uv.lock
+++ b/uv.lock
@@ -149,4 +149,4 @@ wheels = [
 [[package]]
 name = "x4cat"
 version = "0.1.0"
-source = { git = "https://github.com/meethune/x4cat.git#346da177d5fa31b9d52361c9f54ad262c8c88e0a" }
+source = { git = "https://github.com/meethune/x4cat.git#b0e17e142f05ef56aa4859b5d253d317a307b9b7" }