diff --git a/src/common/classes/Aligner.h b/src/common/classes/Aligner.h
index 340a250236..8bf3cb1d12 100644
--- a/src/common/classes/Aligner.h
+++ b/src/common/classes/Aligner.h
@@ -38,7 +38,7 @@ template <typename C>
 class OutAligner
 {
 private:
-	UCHAR* userBuffer;
+	UCHAR* const userBuffer;
 #ifdef RISC_ALIGNMENT
 	Firebird::HalfStaticArray<C, BUFFER_SMALL> localBuffer;
 	ULONG bSize;