diff --git a/src/finiteVolume/fields/fvPatchFields/derived/timeVaryingMappedFixedValue/timeVaryingMappedFixedValueFvPatchField.C b/src/finiteVolume/fields/fvPatchFields/derived/timeVaryingMappedFixedValue/timeVaryingMappedFixedValueFvPatchField.C
index df0623bde1..26c447f345 100644
--- a/src/finiteVolume/fields/fvPatchFields/derived/timeVaryingMappedFixedValue/timeVaryingMappedFixedValueFvPatchField.C
+++ b/src/finiteVolume/fields/fvPatchFields/derived/timeVaryingMappedFixedValue/timeVaryingMappedFixedValueFvPatchField.C
@@ -573,7 +573,7 @@ void Foam::timeVaryingMappedFixedValueFvPatchField<Type>::write
 
     this->writeEntryIfDifferent(os, "setAverage", Switch(false), setAverage_);
 
-    this->writeEntryIfDifferent(os, "perturb", 1e-5, perturb_);
+    this->writeEntryIfDifferent(os, "perturb", scalar(1e-5), perturb_);
 
     this->writeEntryIfDifferent
     (
diff --git a/src/fvMotionSolver/pointPatchFields/derived/timeVaryingMappedFixedValue/timeVaryingMappedFixedValuePointPatchField.C b/src/fvMotionSolver/pointPatchFields/derived/timeVaryingMappedFixedValue/timeVaryingMappedFixedValuePointPatchField.C
index fac9f475b3..ef03e416d6 100644
--- a/src/fvMotionSolver/pointPatchFields/derived/timeVaryingMappedFixedValue/timeVaryingMappedFixedValuePointPatchField.C
+++ b/src/fvMotionSolver/pointPatchFields/derived/timeVaryingMappedFixedValue/timeVaryingMappedFixedValuePointPatchField.C
@@ -598,7 +598,7 @@ void Foam::timeVaryingMappedFixedValuePointPatchField<Type>::write
 
     this->writeEntryIfDifferent(os, "setAverage", Switch(false), setAverage_);
 
-    this->writeEntryIfDifferent(os, "perturb", 1e-5, perturb_);
+    this->writeEntryIfDifferent(os, "perturb", scalar(1e-5), perturb_);
 
     this->writeEntryIfDifferent
     (