diff --git a/RELEASE_NOTES b/RELEASE_NOTES
index 7131ea871..cfb531959 100644
--- a/RELEASE_NOTES
+++ b/RELEASE_NOTES
@@ -31,6 +31,7 @@ Bugs fixed
 - Bug 1930 - Use of invalid reference in OLSR RemoveLinkTuple
 - Bug 1932 - NdiscCache entry is not failsafe on double neighbor probing.
 - Bug 1937 - FlowMonitor fails to track multiplexed packets
+- Bug 1943 - Waveform generator signal duration calc error
 
 Known issues
 ------------
diff --git a/src/spectrum/model/waveform-generator.cc b/src/spectrum/model/waveform-generator.cc
index 3d02bc6e0..7b779b11a 100644
--- a/src/spectrum/model/waveform-generator.cc
+++ b/src/spectrum/model/waveform-generator.cc
@@ -194,7 +194,7 @@ WaveformGenerator::GenerateWaveform ()
   NS_LOG_FUNCTION (this);
 
   Ptr<SpectrumSignalParameters> txParams = Create<SpectrumSignalParameters> ();
-  txParams->duration = Time (m_period * m_dutyCycle);
+  txParams->duration = Time (m_period.GetTimeStep () * m_dutyCycle);
   txParams->psd = m_txPowerSpectralDensity;
   txParams->txPhy = GetObject<SpectrumPhy> ();
   txParams->txAntenna = m_antenna;