diff --git a/.gitattributes b/.gitattributes
new file mode 100644
index 0000000..cda1532
--- /dev/null
+++ b/.gitattributes
@@ -0,0 +1,10 @@
+# Exclude build/test files from archive.
+/tests            export-ignore
+/.editorconfig    export-ignore
+/.gitattributes   export-ignore
+/.gitignore       export-ignore
+/.travis.yml      export-ignore
+/phpunit.xml.dist export-ignore
+
+# Configure diff output for .php files.
+*.php diff=php
diff --git a/.gitignore b/.gitignore
index 22d0d82..7579f74 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,2 @@
 vendor
+composer.lock