diff --git a/src/GraphQLParser/Extensions/ASTNodeExtensions.cs b/src/GraphQLParser/Extensions/ASTNodeExtensions.cs
index 8b528d4..b4f2c0d 100644
--- a/src/GraphQLParser/Extensions/ASTNodeExtensions.cs
+++ b/src/GraphQLParser/Extensions/ASTNodeExtensions.cs
@@ -162,6 +162,6 @@ public static int FragmentsCount(this GraphQLDocument document)
         GraphQLInlineFragment => DirectiveLocation.InlineFragment,
         GraphQLVariableDefinition => DirectiveLocation.VariableDefinition,
 
-        _ => throw new ArgumentOutOfRangeException(nameof(node), "The supplied node cannot")
+        _ => throw new ArgumentOutOfRangeException(nameof(node), "Directives cannot be supplied for the specified node.")
     };
 }