diff --git a/tests_mono.sh b/tests_mono.sh
index 651a87081..52d9a5dfe 100644
--- a/tests_mono.sh
+++ b/tests_mono.sh
@@ -2,9 +2,9 @@ EXCLUDE="-exclude:Windows,IntegrationTest"
 TESTDIR="."
 NUNIT="$TESTDIR/NUnit.Runners.2.6.1/tools/nunit-console-x86.exe"
 
-mono --debug $NUNIT $EXCLUDE -xml:NzbDrone.Api.Result.xml $TESTDIR/NzbDrone.Api.Test.dll
-mono --debug $NUNIT $EXCLUDE -xml:NzbDrone.Common.Result.xml $TESTDIR/NzbDrone.Common.Test.dll
-mono --debug $NUNIT $EXCLUDE -xml:NzbDrone.Core.Result.xml $TESTDIR/NzbDrone.Core.Test.dll
-mono --debug $NUNIT $EXCLUDE -xml:NzbDrone.Host.Result.xml $TESTDIR/NzbDrone.Host.Test.dll
-mono --debug $NUNIT $EXCLUDE -xml:NzbDrone.Libraries.Result.xml $TESTDIR/NzbDrone.Libraries.Test.dll
-mono --debug $NUNIT $EXCLUDE -xml:NzbDrone.Mono.Result.xml $TESTDIR/NzbDrone.Mono.Test.dll
+mono --debug --runtime=v4.0 $NUNIT $EXCLUDE -xml:NzbDrone.Api.Result.xml $TESTDIR/NzbDrone.Api.Test.dll
+mono --debug --runtime=v4.0 $NUNIT $EXCLUDE -xml:NzbDrone.Common.Result.xml $TESTDIR/NzbDrone.Common.Test.dll
+mono --debug --runtime=v4.0 $NUNIT $EXCLUDE -xml:NzbDrone.Core.Result.xml $TESTDIR/NzbDrone.Core.Test.dll
+mono --debug --runtime=v4.0 $NUNIT $EXCLUDE -xml:NzbDrone.Host.Result.xml $TESTDIR/NzbDrone.Host.Test.dll
+mono --debug --runtime=v4.0 $NUNIT $EXCLUDE -xml:NzbDrone.Libraries.Result.xml $TESTDIR/NzbDrone.Libraries.Test.dll
+mono --debug --runtime=v4.0 $NUNIT $EXCLUDE -xml:NzbDrone.Mono.Result.xml $TESTDIR/NzbDrone.Mono.Test.dll