diff --git a/.travis.yml b/.travis.yml
index c0d7c25..518b1b8 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -22,5 +22,6 @@
   - bins/$CONFIG/interop_server --port=5051 --use_tls &
 xcode_workspace: src/objective-c/tests/Tests.xcworkspace
 xcode_scheme: AllTests
+xcode_sdk: iphonesimulator9.1
 notifications:
   email: false