diff --git a/src/Compilers/CSharp/Portable/Symbols/TypeSymbol.cs b/src/Compilers/CSharp/Portable/Symbols/TypeSymbol.cs
index 918b60bd5b723..3f8dae9399887 100644
--- a/src/Compilers/CSharp/Portable/Symbols/TypeSymbol.cs
+++ b/src/Compilers/CSharp/Portable/Symbols/TypeSymbol.cs
@@ -567,7 +567,7 @@ public virtual bool IsAnonymousType
         /// Verify if the given type is a tuple of a given cardinality, or can be used to back a tuple type 
         /// with the given cardinality. 
         /// </summary>
-        public bool IsTupleTypeOfCardinality(int targetCardinality)
+        internal bool IsTupleTypeOfCardinality(int targetCardinality)
         {
             if (IsTupleType)
             {