@@ -994,7 +994,7 @@ def _validate_docs(
                 # see schema translation ideas in the design doc
                 names_compatible = reference_names == input_names
                 types_compatible = all(
-                    (issubclass(t2, t1))
+                    (safe_issubclass(t2, t1))
                     for (t1, t2) in zip(reference_types, input_types)
                 )
                 if names_compatible and types_compatible:
Original file line number	Diff line number	Diff line change
`@@ -994,7 +994,7 @@ def _validate_docs(`
`994`	`994`	`# see schema translation ideas in the design doc`
`995`	`995`	`names_compatible = reference_names == input_names`
`996`	`996`	`types_compatible = all(`
`997`		`- (issubclass(t2, t1))`
	`997`	`+ (safe_issubclass(t2, t1))`
`998`	`998`	`for (t1, t2) in zip(reference_types, input_types)`
`999`	`999`	`)`
`1000`	`1000`	`if names_compatible and types_compatible:`