1 files changed, 1 insertions, 1 deletions
diff --git a/test.f90 b/test.f90
index b5beb0b..38f360f 100644
--- a/test.f90
+++ b/test.f90
@@ -21,7 +21,7 @@ PROGRAM test
 
 CONTAINS
 
-  real(C_DOUBLE) FUNCTION f1(t)
+  PURE real(C_DOUBLE) FUNCTION f1(t)
     real(C_DOUBLE), intent(in) :: t
     real(C_DOUBLE), parameter :: pi = acos(-1.0)