diff --git a/src/coreclr/src/System.Private.CoreLib/src/System/GC.cs b/src/coreclr/src/System.Private.CoreLib/src/System/GC.cs
index e3e1b54373fa5e..a44047cc4d8e95 100644
--- a/src/coreclr/src/System.Private.CoreLib/src/System/GC.cs
+++ b/src/coreclr/src/System.Private.CoreLib/src/System/GC.cs
@@ -353,7 +353,7 @@ public static long GetTotalMemory(bool forceFullCollection)
         }
 
         [DllImport(RuntimeHelpers.QCall, CharSet = CharSet.Unicode)]
-        private static extern IntPtr _RegisterFrozenSegment(IntPtr sectionAddress, IntPtr sectionSize);
+        private static extern IntPtr _RegisterFrozenSegment(IntPtr sectionAddress, nint sectionSize);
 
         [DllImport(RuntimeHelpers.QCall, CharSet = CharSet.Unicode)]
         private static extern void _UnregisterFrozenSegment(IntPtr segmentHandle);