diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..f158e46
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+pmd-bin-*.zip
diff --git a/Dockerfile b/Dockerfile
index 4f1c4bf..b3658d2 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,13 +1,16 @@
 FROM openjdk:13-alpine
 LABEL author="ian@iamthefij.com"
 
-ENV VERSION=6.12.0
+ARG VERSION=6.12.0
 
 RUN apk add bash curl unzip
 
-RUN curl -L -o pmd.zip https://github.com/pmd/pmd/releases/download/pmd_releases%2F${VERSION}/pmd-bin-${VERSION}.zip && \
-        unzip pmd.zip && \
-        rm pmd.zip
+COPY ./pmd-bin-${VERSION}.zip.sha256 /
+
+RUN curl -L -o pmd-bin-${VERSION}.zip https://github.com/pmd/pmd/releases/download/pmd_releases%2F${VERSION}/pmd-bin-${VERSION}.zip && \
+        sha256sum -c pmd-bin-${VERSION}.zip.sha256 && \
+        unzip pmd-bin-${VERSION}.zip && \
+        rm pmd-bin-${VERSION}.zip
 
 RUN mv /pmd-bin-${VERSION} /pmd
 WORKDIR /pmd
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..228b9e7
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,38 @@
+VERSION ?= 6.12.0
+DOCKER_TAG ?= pmd-$(USER)
+SHA256SUM := $(shell which sha256sum || which gsha256sum)
+
+.PHONY: build
+build:
+	docker build --build-arg VERSION=$(VERSION) . -t $(DOCKER_TAG)
+
+.PHONY: run
+run: build
+	docker run --rm $(DOCKER_TAG) --help
+
+# Downloads latest pmd zip
+pmd-bin-$(VERSION).zip:
+	curl -L -o pmd-bin-$(VERSION).zip https://github.com/pmd/pmd/releases/download/pmd_releases%2F$(VERSION)/pmd-bin-$(VERSION).zip
+
+# Generates new sha256 for this version file
+pmd-bin-$(VERSION).zip.sha256: pmd-bin-$(VERSION).zip
+	$(SHA256SUM) pmd-bin-$(VERSION).zip > pmd-bin-$(VERSION).zip.sha256
+
+# Checks that the downloaded file matches the sha sum
+.PHONY: check
+check: 
+	$(SHA256SUM) -c pmd-bin-$(VERSION).zip.sha256
+
+# Updates PMD and generates a new sha
+.PHONY: update
+update: clean pmd-bin-$(VERSION).zip.sha256 check
+
+# Cleans all zips and shas
+.PHONY: clean
+clean:
+	rm -f pmd-bin-*.zip pmd-bin-*.zip.sha256
+
+# Creates a git tag for the current pmd version
+.PHONY: tag
+tag:
+	git tag -v $(VERSION)
diff --git a/pmd-bin-6.12.0.zip.sha256 b/pmd-bin-6.12.0.zip.sha256
new file mode 100644
index 0000000..040bab2
--- /dev/null
+++ b/pmd-bin-6.12.0.zip.sha256
@@ -0,0 +1 @@
+e61b3855bd94c1a3875b788cfd252a2d4f1232d47a41479078640da9aa3f7ecb  pmd-bin-6.12.0.zip