diff --git a/Common/processfields_fd.cpp b/Common/processfields_fd.cpp
index dd362d0..68227dc 100644
--- a/Common/processfields_fd.cpp
+++ b/Common/processfields_fd.cpp
@@ -94,7 +94,7 @@ int ProcessFieldsFD::Process()
 	{
 		std::complex<float> exp_jwt_2_dt = std::exp( (std::complex<float>)(-2.0 * _I * M_PI * m_FD_Samples.at(n) * T) );
 		exp_jwt_2_dt *= 2; // *2 for single-sided spectrum
-		exp_jwt_2_dt *= Op->GetTimestep(); // multiply with timestep
+		exp_jwt_2_dt *= Op->GetTimestep() * m_FD_Interval; // multiply with timestep-interval
 		field_fd = m_FD_Fields.at(n);
 		for (pos[0]=0; pos[0]<numLines[0]; ++pos[0])
 		{
diff --git a/Common/processintegral.cpp b/Common/processintegral.cpp
index 9aa37b4..448e937 100644
--- a/Common/processintegral.cpp
+++ b/Common/processintegral.cpp
@@ -149,7 +149,7 @@ int ProcessIntegral::Process()
 			for (size_t n=0; n<m_FD_Samples.size(); ++n)
 			{
 				for (int i=0; i<NrInt; ++i)
-					m_FD_Results[i].at(n) += (double)m_Results[i] * m_weight * std::exp( -2.0 * _I * M_PI * m_FD_Samples.at(n) * time ) * 2.0 * Op->GetTimestep();
+					m_FD_Results[i].at(n) += (double)m_Results[i] * m_weight * std::exp( -2.0 * _I * M_PI * m_FD_Samples.at(n) * time ) * 2.0 * Op->GetTimestep() * (double)m_FD_Interval;
 			}
 			++m_FD_SampleCount;
 			if (m_Flush)