diff --git a/src/Singletop_SCET/nnlotopdecay.f b/src/Singletop_SCET/nnlotopdecay.f
index 6995a98..620563e 100644
--- a/src/Singletop_SCET/nnlotopdecay.f
+++ b/src/Singletop_SCET/nnlotopdecay.f
@@ -53,7 +53,7 @@ c***********************************************************************
       be=mb/mt
       besq=be**2
 
-      if (zerowidth) then
+      if (zerowidth .or. (gamw == 0._dp)) then
           omsq=om**2
           lotopdecaywidth=Gamma0(mt,besq,omsq)
       else