diff --git a/src/libraries/System.Private.CoreLib/src/System/Environment.Windows.cs b/src/libraries/System.Private.CoreLib/src/System/Environment.Windows.cs
index bd2cb5b10ff3f..b7bc78760e326 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Environment.Windows.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Environment.Windows.cs
@@ -131,7 +131,7 @@ private static unsafe bool IsPrivilegedProcessCore()
             uint length;
             while ((length = Interop.Kernel32.GetModuleFileName(IntPtr.Zero, ref builder.GetPinnableReference(), (uint)builder.Capacity)) >= builder.Capacity)
             {
-                builder.EnsureCapacity((int)length);
+                builder.EnsureCapacity(builder.Length * 2);
             }
 
             if (length == 0)