diff --git a/framework/src/source/rooibos/BaseTestSuite.bs b/framework/src/source/rooibos/BaseTestSuite.bs
index 7caf2645..6db66780 100644
--- a/framework/src/source/rooibos/BaseTestSuite.bs
+++ b/framework/src/source/rooibos/BaseTestSuite.bs
@@ -541,7 +541,7 @@ namespace rooibos
       end if
 
       try
-        if type(value) <> "Invalid"
+        if rooibos.common.getSafeType(value) <> "Invalid"
           if msg = ""
             actual = rooibos.common.asMultilineString(value, true)
             msg = `expected "${rooibos.common.truncateString(actual)}" to be invalid`
@@ -573,7 +573,7 @@ namespace rooibos
         return false
       end if
       try
-        if value = invalid
+        if rooibos.common.getSafeType(value) = "Invalid"
           if msg = ""
             actual = rooibos.common.asMultilineString(value, true)
             msg = `expected "${rooibos.common.truncateString(actual)}" to not be invalid`