diff --git a/Makefile b/Makefile
index f9b50a2..ce8af42 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,14 @@
-.phony: test
+.phony: test-all test-changed update-tests
 
-test:
-	@bats -T -r .
+BASE_REF ?= origin/master
+
+all: test-changed
+
+test-all:
+	@bats -T $(shell find . -name test.bats| sort )
+
+test-changed:
+	@bats -T $(shell git diff --name-status ${BASE_REF} | awk '{print $2}' | xargs dirname | uniq | grep -v -E '^(\.|lib)' | xargs -I% echo -n " %/test.bats" )
 
 update-tests:
 	@find . -maxdepth 1 -type d -not -path '*/\.*' -not -path '.' -not -path './lib' -exec cp ./lib/test.bats.example {}/test.bats \;