diff --git a/graphene/types/utils.py b/graphene/types/utils.py
index 3b195d69..1976448a 100644
--- a/graphene/types/utils.py
+++ b/graphene/types/utils.py
@@ -41,3 +41,10 @@ def get_type(_type):
     if inspect.isfunction(_type) or isinstance(_type, partial):
         return _type()
     return _type
+
+
+def get_underlying_type(_type):
+    """Get the underlying type even if it is wrapped in structures like NonNull"""
+    while hasattr(_type, "of_type"):
+        _type = _type.of_type
+    return _type