diff --git a/src/mesa/main/texenvprogram.c b/src/mesa/main/texenvprogram.c
index bce570b3b2c..5f798cc7df4 100644
--- a/src/mesa/main/texenvprogram.c
+++ b/src/mesa/main/texenvprogram.c
@@ -258,7 +258,7 @@ struct ureg {
 };
 
 static const struct ureg undef = { 
-   ~0,
+   PROGRAM_UNDEFINED,
    ~0,
    0,
    0,
@@ -334,7 +334,7 @@ static struct ureg negate( struct ureg reg )
 
 static GLboolean is_undef( struct ureg reg )
 {
-   return reg.file == 0xf;
+   return reg.file == PROGRAM_UNDEFINED;
 }