diff --git a/src/NJsonSchema/JsonPathUtilities.cs b/src/NJsonSchema/JsonPathUtilities.cs
index e83462399..6d1bf0dd4 100644
--- a/src/NJsonSchema/JsonPathUtilities.cs
+++ b/src/NJsonSchema/JsonPathUtilities.cs
@@ -63,8 +63,10 @@ public static class JsonPathUtilities
 
             if (mappings.Any(p => p.Value == null))
             {
+                var errorItems = mappings.Where(p => p.Value == null).Select(x => x.Key.GetType().FullName);
                 throw new InvalidOperationException("Could not find the JSON path of a referenced schema: " +
-                                                    "Manually referenced schemas must be added to the " +
+                                                     string.Join(",", errorItems) +
+                                                    ". Manually referenced schemas must be added to the " +
                                                     "'Definitions' of a parent schema.");
             }
 
@@ -177,4 +179,4 @@ private static bool FindJsonPaths(object obj, Dictionary<object, string?> search
             return false;
         }
     }
-}
\ No newline at end of file
+}