diff --git a/Sample/FFCompute/IComputeFF.cpp b/Sample/FFCompute/IComputeFF.cpp
index df473134dfc30639189152b92807a906a29b06a4..e372996967a91b3b270225d09f56933815835406 100644
--- a/Sample/FFCompute/IComputeFF.cpp
+++ b/Sample/FFCompute/IComputeFF.cpp
@@ -13,6 +13,7 @@
 //  ************************************************************************************************
 
 #include "Sample/FFCompute/IComputeFF.h"
+#include "Sample/RT/ILayerRTCoefficients.h" // required by VS19 compiler
 #include "Sample/Scattering/IFormFactor.h"
 #include <stdexcept>