diff --git a/Tusker.xcodeproj/xcshareddata/xcschemes/Tusker.xcscheme b/Tusker.xcodeproj/xcshareddata/xcschemes/Tusker.xcscheme
index a6172ec3..92941e2f 100644
--- a/Tusker.xcodeproj/xcshareddata/xcschemes/Tusker.xcscheme
+++ b/Tusker.xcodeproj/xcshareddata/xcschemes/Tusker.xcscheme
@@ -99,6 +99,11 @@
             value = "1"
             isEnabled = "NO">
          </EnvironmentVariable>
+         <EnvironmentVariable
+            key = "LIBDISPATCH_COOPERATIVE_POOL_STRICT"
+            value = "1"
+            isEnabled = "YES">
+         </EnvironmentVariable>
       </EnvironmentVariables>
    </LaunchAction>
    <ProfileAction