diff --git a/src/TurbulenceModels/compressible/turbulentFluidThermoModels/derivedFvPatchFields/externalWallHeatFluxTemperature/externalWallHeatFluxTemperatureFvPatchScalarField.C b/src/TurbulenceModels/compressible/turbulentFluidThermoModels/derivedFvPatchFields/externalWallHeatFluxTemperature/externalWallHeatFluxTemperatureFvPatchScalarField.C
index 3fac6847e7d38d092f59f4158f3abbf9875e4aad..f87c8c9b394ea5a2045db945187d94a355d9a96e 100644
--- a/src/TurbulenceModels/compressible/turbulentFluidThermoModels/derivedFvPatchFields/externalWallHeatFluxTemperature/externalWallHeatFluxTemperatureFvPatchScalarField.C
+++ b/src/TurbulenceModels/compressible/turbulentFluidThermoModels/derivedFvPatchFields/externalWallHeatFluxTemperature/externalWallHeatFluxTemperatureFvPatchScalarField.C
@@ -215,6 +215,7 @@ externalWallHeatFluxTemperatureFvPatchScalarField
 
     if (qrName_ != "none")
     {
+        qrPrevious_.setSize(mapper.size());
         qrPrevious_.map(ptf.qrPrevious_, mapper);
     }
 }