diff --git a/lib/decoder.f90 b/lib/decoder.f90
index 8e9033e4e..3e5b2573d 100644
--- a/lib/decoder.f90
+++ b/lib/decoder.f90
@@ -194,7 +194,8 @@ subroutine multimode_decoder(ss,id2,params,nfsample)
      params%nsubmode=0
      call timer('dec240  ',0)
      call my_fst4%decode(fst4_decoded,id2,params%nutc,                &
-          params%nQSOProgress,params%nfqso,ndepth,params%ntr,         &
+          params%nQSOProgress,params%nfa,params%nfb,                  &
+          params%nfqso,ndepth,params%ntr,                             &
           params%nexp_decode,params%ntol,params%emedelay,             &
           logical(params%lapcqonly),mycall,hiscall,iwspr)
      call timer('dec240  ',1)
@@ -207,7 +208,8 @@ subroutine multimode_decoder(ss,id2,params,nfsample)
      iwspr=1
      call timer('dec240  ',0)
      call my_fst4%decode(fst4_decoded,id2,params%nutc,                &
-          params%nQSOProgress,params%nfqso,ndepth,params%ntr,         &
+          params%nQSOProgress,params%nfa,params%nfb,                  &
+          params%nfqso,ndepth,params%ntr,                             &
           params%nexp_decode,params%ntol,params%emedelay,             &
           logical(params%lapcqonly),mycall,hiscall,iwspr)
      call timer('dec240  ',1)
diff --git a/lib/fst4_decode.f90 b/lib/fst4_decode.f90
index 33f383810..8ec889b36 100644
--- a/lib/fst4_decode.f90
+++ b/lib/fst4_decode.f90
@@ -29,8 +29,8 @@ module fst4_decode
 
 contains
 
-   subroutine decode(this,callback,iwave,nutc,nQSOProgress,nfqso,      &
-        ndepth,ntrperiod,nexp_decode,ntol,emedelay,lapcqonly,mycall,   &
+   subroutine decode(this,callback,iwave,nutc,nQSOProgress,nfa,nfb,nfqso, &
+        ndepth,ntrperiod,nexp_decode,ntol,emedelay,lapcqonly,mycall,      &
         hiscall,iwspr)
 
       use timer_module, only: timer