diff --git a/python/psi-api/src/com/jetbrains/python/psi/types/PyTypeProviderBase.java b/python/psi-api/src/com/jetbrains/python/psi/types/PyTypeProviderBase.java
index ce4bc351c832..6afadebaf953 100644
--- a/python/psi-api/src/com/jetbrains/python/psi/types/PyTypeProviderBase.java
+++ b/python/psi-api/src/com/jetbrains/python/psi/types/PyTypeProviderBase.java
@@ -60,6 +60,7 @@ public class PyTypeProviderBase implements PyTypeProvider {
   }
 
   @Override
+  @Nullable
   public Ref<PyType> getParameterType(@NotNull PyNamedParameter param, @NotNull PyFunction func, @NotNull TypeEvalContext context) {
     return null;
   }