diff --git a/GTE/Mathematics/ApprPolynomialSpecial4.h b/GTE/Mathematics/ApprPolynomialSpecial4.h
index 2879e7c9..9a152953 100644
--- a/GTE/Mathematics/ApprPolynomialSpecial4.h
+++ b/GTE/Mathematics/ApprPolynomialSpecial4.h
@@ -3,7 +3,7 @@
 // Distributed under the Boost Software License, Version 1.0.
 // https://www.boost.org/LICENSE_1_0.txt
 // https://www.geometrictools.com/License/Boost/LICENSE_1_0.txt
-// File Version: 8.0.2025.05.10
+// File Version: 8.0.2026.02.16
 
 #pragma once
 
@@ -196,7 +196,7 @@ namespace gte
             {
                 Real xp = mXPowers[mXDegrees[i]];
                 Real yp = mYPowers[mYDegrees[i]];
-                Real zp = mYPowers[mZDegrees[i]];
+                Real zp = mZPowers[mZDegrees[i]];
                 w += mParameters[i] * xp * yp * zp;
             }