diff --git a/src/finiteVolume/fields/fvPatchFields/derived/prghUniformDensityHydrostaticPressure/prghUniformDensityHydrostaticPressureFvPatchScalarField.H b/src/finiteVolume/fields/fvPatchFields/derived/prghUniformDensityHydrostaticPressure/prghUniformDensityHydrostaticPressureFvPatchScalarField.H
index 53538b26f8..6db5e912bc 100644
--- a/src/finiteVolume/fields/fvPatchFields/derived/prghUniformDensityHydrostaticPressure/prghUniformDensityHydrostaticPressureFvPatchScalarField.H
+++ b/src/finiteVolume/fields/fvPatchFields/derived/prghUniformDensityHydrostaticPressure/prghUniformDensityHydrostaticPressureFvPatchScalarField.H
@@ -32,7 +32,7 @@ Description
     calculated as:
 
         \f[
-            p_{rgh} = p_{ref} - (\rho - \rho_0) g (h - h_{ref})
+            p_{rgh} = p_{ref} - (\rho - \rho_{ref}) g (h - h_{ref})
         \f]
 
     where