diff --git a/library/havege.c b/library/havege.c
index 7623bc0..2b75ef7 100644
--- a/library/havege.c
+++ b/library/havege.c
@@ -174,6 +174,8 @@
     PTX  = U1 = 0;
     PTY  = U2 = 0;
 
+    (void)PTX;
+
     memset( RES, 0, sizeof( RES ) );
 
     while( n < MBEDTLS_HAVEGE_COLLECT_SIZE * 4 )