diff --git a/lib/extract.f90 b/lib/extract.f90
index 0674ccaba..2bc262e0b 100644
--- a/lib/extract.f90
+++ b/lib/extract.f90
@@ -30,6 +30,7 @@ subroutine extract(s3,nadd,mode65,ntrials,naggressive,ndepth,nflip,     &
   common/chansyms65/correct
   save
 
+  if(mode65.eq.-99) stop                   !Silence compiler warning
   mycall=mycall_12(1:6)
   hiscall=hiscall_12(1:6)
   qual=0.
@@ -94,8 +95,7 @@ subroutine extract(s3,nadd,mode65,ntrials,naggressive,ndepth,nflip,     &
   if(nft.eq.0 .and. iand(ndepth,32).eq.32) then
      qmin=2.0 - 0.1*naggressive
      call timer('hint65  ',0)
-     call hint65(s3,mrs,mrs2,mrsym,mr2sym,mrprob,nadd,nflip,   &
-          mycall,hiscall,hisgrid,nexp_decode,qual,decoded)
+     call hint65(s3,mrs,mrs2,nadd,nflip,mycall,hiscall,hisgrid,qual,decoded)
      if(qual.ge.qmin) then
         nft=2
         ncount=0
diff --git a/lib/genmsk144.f90 b/lib/genmsk144.f90
index 7b05c8697..7a286f5e8 100644
--- a/lib/genmsk144.f90
+++ b/lib/genmsk144.f90
@@ -39,8 +39,7 @@ subroutine genmsk144(msg0,ichk,msgsent,i4tone,itype,pchk_file)
   integer*1 b11(11)
   integer*1 b13(13)
   real*8 pp(12)
-  real*8 xi(864),xq(864),pi,twopi,phi,dphi
-  real waveform(864)
+  real*8 xi(864),xq(864),pi,twopi
   data b7/1,1,1,0,0,1,0/
   data s8/0,1,1,1,0,0,1,0/
   data b11/1,1,1,0,0,0,1,0,0,1,0/         !Barker 11 code
diff --git a/lib/hint65.f90 b/lib/hint65.f90
index 8d7c5b73f..df6c297fb 100644
--- a/lib/hint65.f90
+++ b/lib/hint65.f90
@@ -1,5 +1,4 @@
-subroutine hint65(s3,mrs,mrs2,mrsym,mr2sym,mrprob,nadd,nflip,   &
-     mycall,hiscall,hisgrid,nexp_decode,qual,decoded)
+subroutine hint65(s3,mrs,mrs2,nadd,nflip,mycall,hiscall,hisgrid,qual,decoded)
 
   use packjt
   use prog_args
@@ -9,7 +8,6 @@ subroutine hint65(s3,mrs,mrs2,mrsym,mr2sym,mrprob,nadd,nflip,   &
   integer*1 sym1(0:62,MAXMSG)
   integer*1 sym2(0:62,MAXMSG)
   integer mrs(63),mrs2(63)
-  integer mrsym(0:62),mr2sym(0:62),mrprob(0:62)
   integer dgen(12),sym(0:62),sym_rev(0:62)
   character*6 mycall,hiscall,hisgrid,call2(MAXCALLS)
   character*4 grid2(MAXCALLS),rpt(MAXRPT)
diff --git a/lib/jt65_test.f90 b/lib/jt65_test.f90
index 914824247..f146f82bd 100644
--- a/lib/jt65_test.f90
+++ b/lib/jt65_test.f90
@@ -60,6 +60,7 @@ contains
     integer nwidth
     real t
 
+    if(minsync+nflip+qual.eq.-9999) stop            !Silence compiler warning
     t=max(0.0,width*width-7.2)
     nwidth=max(nint(sqrt(t)),2)
 !### deal with nflip here! ###
diff --git a/lib/msk144_decode.f90 b/lib/msk144_decode.f90
index 3a914a7bd..8cf10050e 100644
--- a/lib/msk144_decode.f90
+++ b/lib/msk144_decode.f90
@@ -11,7 +11,6 @@ subroutine msk144_decode(id2,npts,nutc,nprint,pchk_file,line)
   real ty(NMAX/512)                    !Ping times
   real yellow(NMAX/512)
   complex c(NFFTMAX)                   !Complex (analytic) data
-  complex cdat(24000)                  !Short segments, up to 2 s
   complex cdat2(24000)
   character*22 msg,msg0                !Decoded message
   character*80 line(100)               !Decodes passed back to caller
diff --git a/lib/msk144d.f90 b/lib/msk144d.f90
index e277b011a..7bbbc78a9 100644
--- a/lib/msk144d.f90
+++ b/lib/msk144d.f90
@@ -7,7 +7,7 @@ program msk144d
   use timer_impl, only: init_timer
   use readwav
 
-  character c,mode
+  character c
   character*80 line(100)
   character*512 pchk_file
   logical :: display_help=.false.
diff --git a/lib/msk144sim.f90 b/lib/msk144sim.f90
index 53b8cba02..32d8ab6ff 100644
--- a/lib/msk144sim.f90
+++ b/lib/msk144sim.f90
@@ -8,7 +8,7 @@ program msk144sim
   character*512 pchk_file
   character*3 rpt(0:7)
   real wave(0:NMAX-1)              !Simulated received waveform
-  real*8 dt,twopi,freq,phi,dphi0,dphi1,dphi
+  real*8 twopi,freq,phi,dphi0,dphi1,dphi
   type(hdr) h                          !Header for .wav file
   integer*2 iwave(0:NMAX-1)
   integer itone(144)                   !Message bits
diff --git a/lib/softsym9w.f90 b/lib/softsym9w.f90
index 266b9314c..4465e0ead 100644
--- a/lib/softsym9w.f90
+++ b/lib/softsym9w.f90
@@ -12,6 +12,7 @@ subroutine softsym9w(id2,npts,xdt0,f0,width,nsubmode,xdt1,i1softsymbols)
   include 'jt9sync.f90'
   equivalence (x,cx)
 
+  if(npts.eq.-99) stop                     !Silence compiler warning
   df=12000.0/NFFT
   i0a=max(1.0,(xdt0-1.0)*12000.0)
   i0b=(xdt0+1.0)*12000.0
diff --git a/lib/sync65.f90 b/lib/sync65.f90
index e623654c1..786a80312 100644
--- a/lib/sync65.f90
+++ b/lib/sync65.f90
@@ -17,6 +17,7 @@ subroutine sync65(ss,nfa,nfb,naggressive,ntol,nhsym,ca,ncand,nrobust,   &
 
   common/steve/thresh0
 
+  if(ntol.eq.-99) stop                       !Silence compiler warning
   call setup65
   df=12000.0/NFFT                            !df = 12000.0/8192 = 1.465 Hz
   ia=max(2,nint(nfa/df))
diff --git a/lib/syncmsk144.f90 b/lib/syncmsk144.f90
index 058d1a8de..cbe4546f1 100644
--- a/lib/syncmsk144.f90
+++ b/lib/syncmsk144.f90
@@ -13,7 +13,7 @@ subroutine syncmsk144(cdat,npts,pchk_file,msgreceived,fest,nutc,t0)
   complex c(NSPM)
   complex ctmp(6000)                  
   complex cb(42)                        !Complex waveform for sync word 
-  complex csum,cfac,cca,ccb
+  complex cfac,cca,ccb
   complex cc(npts)
   complex cc1(npts)
   complex cc2(npts)
@@ -21,10 +21,8 @@ subroutine syncmsk144(cdat,npts,pchk_file,msgreceived,fest,nutc,t0)
   integer s8(8),hardbits(144),hardword(128),unscrambledhardbits(128)
   integer*1, target:: i1Dec8BitBytes(10)
   integer, dimension(1) :: iloc
-  integer*4 i4Msg6BitWords(12)          !72-bit message as 6-bit words
   integer*4 i4Dec6BitWords(12)  
   integer*1 decoded(80)   
-  integer*1, allocatable :: message(:)
   integer*1 i1hashdec
   integer ipeaks(10)
   logical ismask(6000)
@@ -41,7 +39,7 @@ subroutine syncmsk144(cdat,npts,pchk_file,msgreceived,fest,nutc,t0)
   data first/.true./
 
   data s8/0,1,1,1,0,0,1,0/
-  save first,cb,pi,twopi,dt,f0,f1
+  save first,cb,pi,twopi,dt
 
   if(first) then
      i=index(pchk_file,".pchk")