diff --git a/tools_webrtc/ios/client.webrtc/iOS64_Sim_Debug_(iOS_10.0).json b/tools_webrtc/ios/client.webrtc/iOS64_Sim_Debug_(iOS_10.0).json
index 708f3ce48a..93493f6579 100644
--- a/tools_webrtc/ios/client.webrtc/iOS64_Sim_Debug_(iOS_10.0).json
+++ b/tools_webrtc/ios/client.webrtc/iOS64_Sim_Debug_(iOS_10.0).json
@@ -22,7 +22,8 @@
       "dimensions": [
         {
           "os": "Mac-10.12",
-          "pool": "Chrome"
+          "pool": "Chrome",
+          "xcode_version": "9.0"
         },
         {
           "os": "Mac-10.13.3",
diff --git a/tools_webrtc/ios/tryserver.webrtc/ios64_sim_ios10_dbg.json b/tools_webrtc/ios/tryserver.webrtc/ios64_sim_ios10_dbg.json
index 70c9976e60..85c347813e 100644
--- a/tools_webrtc/ios/tryserver.webrtc/ios64_sim_ios10_dbg.json
+++ b/tools_webrtc/ios/tryserver.webrtc/ios64_sim_ios10_dbg.json
@@ -23,7 +23,8 @@
       "dimensions": [
         {
           "os": "Mac-10.12",
-          "pool": "Chrome"
+          "pool": "Chrome",
+          "xcode_version": "9.0"
         },
         {
           "os": "Mac-10.13.3",