diff --git a/.mergify.yml b/.mergify.yml
new file mode 100644
index 0000000..4cedc6c
--- /dev/null
+++ b/.mergify.yml
@@ -0,0 +1,44 @@
+pull_request_rules:
+  - name: remove outdated reviews
+    conditions:
+      - base=master
+    actions:
+      dismiss_reviews: {}
+  - name: automatically approve PR when pushed by me
+    conditions:
+      - author=tkf
+      - base=master
+      - status-success=Travis CI - Pull Request
+      - label~=ready-to-merge:.*
+    actions:
+      review: {}
+  - name: automatic squash-merge when CI passes
+    conditions:
+      - base=master
+      - "#approved-reviews-by>=1"
+      - status-success=Travis CI - Pull Request
+      - label=ready-to-merge:squash
+      - label!=work-in-progress
+    actions:
+      merge:
+        method: squash
+  - name: automatic rebase-merge when CI passes
+    conditions:
+      - base=master
+      - "#approved-reviews-by>=1"
+      - status-success=Travis CI - Pull Request
+      - label=ready-to-merge:rebase
+      - label!=work-in-progress
+    actions:
+      merge:
+        method: rebase
+  - name: automatic merge when CI passes
+    conditions:
+      - base=master
+      - "#approved-reviews-by>=1"
+      - status-success=Travis CI - Pull Request
+      - label=ready-to-merge:merge
+      - label!=work-in-progress
+    actions:
+      merge:
+        method: merge
diff --git a/.travis.yml b/.travis.yml
index 5009c82..79aa2ff 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -13,5 +13,10 @@ notifications:
 git:
   depth: 99999999
 
+# Only build branches via PR to avoid running CI twice.
+# https://docs.travis-ci.com/user/conditional-builds-stages-jobs
+# https://docs.travis-ci.com/user/conditions-v1
+if: branch = master OR tag IS present OR type != push
+
 coveralls: true
 codecov: true