diff --git a/tools_webrtc/ios/client.webrtc/iOS32_Sim_Debug_(iOS_9.0).json b/tools_webrtc/ios/client.webrtc/iOS32_Sim_Debug_(iOS_9.0).json
index 395753111f..7a56d46180 100644
--- a/tools_webrtc/ios/client.webrtc/iOS32_Sim_Debug_(iOS_9.0).json
+++ b/tools_webrtc/ios/client.webrtc/iOS32_Sim_Debug_(iOS_9.0).json
@@ -20,14 +20,9 @@
       "device type": "iPhone 5",
       "os": "9.3",
       "dimensions": [
-        {
-          "os": "Mac-10.12",
-          "pool": "Chrome"
-        },
-        {
-          "os": "Mac-10.13",
-          "pool": "Chrome"
-        }
+        { "os": "Mac-10.13.4", "pool": "Chrome" },
+        { "os": "Mac-10.13.5", "pool": "Chrome" },
+        { "os": "Mac-10.13.6", "pool": "Chrome" }
       ]
     }
   ]
diff --git a/tools_webrtc/ios/client.webrtc/iOS64_Sim_Debug_(iOS_11.0).json b/tools_webrtc/ios/client.webrtc/iOS64_Sim_Debug_(iOS_11.0).json
index 18e168357c..3dad91ba64 100644
--- a/tools_webrtc/ios/client.webrtc/iOS64_Sim_Debug_(iOS_11.0).json
+++ b/tools_webrtc/ios/client.webrtc/iOS64_Sim_Debug_(iOS_11.0).json
@@ -20,14 +20,9 @@
       "device type": "iPhone 7",
       "os": "11.0",
       "dimensions": [
-        {
-          "os": "Mac-10.12",
-          "pool": "Chrome"
-        },
-        {
-          "os": "Mac-10.13",
-          "pool": "Chrome"
-        }
+        { "os": "Mac-10.13.4", "pool": "Chrome" },
+        { "os": "Mac-10.13.5", "pool": "Chrome" },
+        { "os": "Mac-10.13.6", "pool": "Chrome" }
       ]
     }
   ]
diff --git a/tools_webrtc/ios/client.webrtc/iOS64_Sim_Debug_(iOS_9.0).json b/tools_webrtc/ios/client.webrtc/iOS64_Sim_Debug_(iOS_9.0).json
index 7c957b100d..d27cdaa45f 100644
--- a/tools_webrtc/ios/client.webrtc/iOS64_Sim_Debug_(iOS_9.0).json
+++ b/tools_webrtc/ios/client.webrtc/iOS64_Sim_Debug_(iOS_9.0).json
@@ -20,14 +20,9 @@
       "device type": "iPhone 6s",
       "os": "9.3",
       "dimensions": [
-        {
-          "os": "Mac-10.12",
-          "pool": "Chrome"
-        },
-        {
-          "os": "Mac-10.13",
-          "pool": "Chrome"
-        }
+        { "os": "Mac-10.13.4", "pool": "Chrome" },
+        { "os": "Mac-10.13.5", "pool": "Chrome" },
+        { "os": "Mac-10.13.6", "pool": "Chrome" }
       ]
     }
   ]