diff --git a/src/physical_constants.c b/src/physical_constants.c
index 646dd7f52defbdf73a48ad9d53f98514f0669554..5996712238188116cc6ba32217f9807be7c71969 100644
--- a/src/physical_constants.c
+++ b/src/physical_constants.c
@@ -142,7 +142,7 @@ void phys_const_init(const struct unit_system *us, struct swift_params *params,
       const_kennicutt_schmidt_units_cgs / 
       units_general_cgs_conversion_factor(us, dimension_ks);
   
-  const float dimension_M_per_pc2 = {1, -2, 0, 0, 0};
+  const float dimension_M_per_pc2[5] = {1, -2, 0, 0, 0};
   internal_const->const_solar_mass_per_parsec2 = 
       const_solar_mass_per_squared_parsec / 
       units_general_cgs_conversion_factor(us, dimension_M_per_pc2);