diff --git a/maps/src/FlatSkyProjection.cxx b/maps/src/FlatSkyProjection.cxx
index e3f0bc01..5913a058 100644
--- a/maps/src/FlatSkyProjection.cxx
+++ b/maps/src/FlatSkyProjection.cxx
@@ -196,8 +196,8 @@ void FlatSkyProjection::SetDeltaCenter(double delta)
 	if (fabs(delta) > 90 * deg)
 		log_fatal("Delta center out of range");
 	delta0_ = delta;
-	cosdelta0_ = COS(delta0_ / rad);
 	sindelta0_ = SIN(delta0_ / rad);
+	cosdelta0_ = COS(delta0_ / rad);
 	q0_ = get_origin_rotator(alpha0_, delta0_);
 }