diff --git a/src/libraries/System.Private.CoreLib/src/System/Runtime/CompilerServices/CastCache.cs b/src/libraries/System.Private.CoreLib/src/System/Runtime/CompilerServices/CastCache.cs
index 7653749d5d5f28..22f9e762d473b5 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Runtime/CompilerServices/CastCache.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Runtime/CompilerServices/CastCache.cs
@@ -250,7 +250,7 @@ internal static CastResult TryGet(int[] table, nuint source, nuint target)
             TableMask(ref tableData) = size - 1;
 
             // Fibonacci hash reduces the value into desired range by shifting right by the number of leading zeroes in 'size-1'
-            byte shift = (byte)BitOperations.LeadingZeroCount(size - 1);
+            byte shift = (byte)BitOperations.LeadingZeroCount((nuint)(size - 1));
             HashShift(ref tableData) = shift;
 
             return table;
diff --git a/src/libraries/System.Private.CoreLib/src/System/Runtime/CompilerServices/GenericCache.cs b/src/libraries/System.Private.CoreLib/src/System/Runtime/CompilerServices/GenericCache.cs
index 712f5ed924645c..31bd1ff9b50fe6 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Runtime/CompilerServices/GenericCache.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Runtime/CompilerServices/GenericCache.cs
@@ -230,7 +230,7 @@ internal bool TryGet(TKey key, out TValue? value)
             ref Entry tableData = ref TableData(table);
 
             // Fibonacci hash reduces the value into desired range by shifting right by the number of leading zeroes in 'size-1'
-            byte shift = (byte)BitOperations.LeadingZeroCount(size - 1);
+            byte shift = (byte)BitOperations.LeadingZeroCount((nuint)(size - 1));
             HashShift(table) = shift;
 
             return table;