diff --git a/test/fortran/test_math_utilities.f90 b/test/fortran/test_math_utilities.f90
index 25064f5958e2896916133dcaded7e48d6d24d74b..70fd9ab6fe34b7371307143aa4463177a5a55edc 100644
--- a/test/fortran/test_math_utilities.f90
+++ b/test/fortran/test_math_utilities.f90
@@ -24,7 +24,7 @@ MODULE TEST_mo_math_utilities
   PRIVATE
 
   PUBLIC :: TEST_cc2gc, TEST_gc2cc, TEST_cc2tv, TEST_gvec2cvec, TEST_cvec2gvec, TEST_tdma_solver_vec
-  REAL(wp), PARAMETER :: earth_radius           = 6.371229e6_wp    !! [m]    average radius
+  REAL(wp), PARAMETER :: earth_radius = 6.371229e6_wp !! [m]    average radius
 
 CONTAINS