diff --git a/astronomy/astronomy.F90 b/astronomy/astronomy.F90
index 5cf5063582..c133cbde22 100644
--- a/astronomy/astronomy.F90
+++ b/astronomy/astronomy.F90
@@ -498,7 +498,7 @@ subroutine astronomy_init (latb, lonb)
 !---------------------------------------------------------------------
 !>    Define useful module variables.
 !----------------------------------------------------------------------
-    twopi = 2.0_r8_kind * real(PI, r8_kind)
+    twopi = 2.0_r8_kind * PI
     deg_to_rad = twopi/360.0_r8_kind
 
 !---------------------------------------------------------------------