diff --git a/CMakeLists.txt b/CMakeLists.txt
index c6d19c6a9..3f7d8072f 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -416,6 +416,7 @@ set_source_files_properties (${ka9q_CSRCS} PROPERTIES COMPILE_FLAGS -Wno-sign-co
 set (wsjt_CSRCS
   ${ka9q_CSRCS}
   lib/ftrsd/ftrsd2.c
+  lib/sgran.c
   lib/gran.c
   lib/igray.c
   lib/init_random_seed.c
diff --git a/lib/JTMSKsim.f90 b/lib/JTMSKsim.f90
index 2a823d948..c9a17d605 100644
--- a/lib/JTMSKsim.f90
+++ b/lib/JTMSKsim.f90
@@ -41,6 +41,9 @@ program JTMSKsim
   phi0=0.
   sig=10.0**(0.05*snrdb)
 
+  call init_random_seed(1)      ! seed Fortran RANDOM_NUMBER generator
+  call sgran()                  ! see C rand generator (used in gran)
+
 ! Generate the Tx waveform
   cb11=0.
   do j=1,234
diff --git a/lib/chkfft.f90 b/lib/chkfft.f90
index 84208a91e..f0ab4e8a6 100644
--- a/lib/chkfft.f90
+++ b/lib/chkfft.f90
@@ -42,6 +42,8 @@ program chkfft
   call getarg(5,arg)
   read(arg,*) npatience
 
+  call sgran()
+
   if(list) write(*,1000) infile,nr,nw,ncomplex,npatience
 1000 format(/'infile: ',a12,'   nr:',i2,'   nw',i2,'   nc:',i2,'   np:',i2/)
   if(.not.list) write(*,1002) nfft,nr,nw,ncomplex,npatience
diff --git a/lib/genmet.f90 b/lib/genmet.f90
index 0682bf80b..81f2e56d4 100644
--- a/lib/genmet.f90
+++ b/lib/genmet.f90
@@ -33,6 +33,8 @@ program genmet
   hist=0
   nerr=0
 
+  call sgran()
+
   do iter=1,iters
      do i=0,ntones-1
         r(i)=0.
diff --git a/lib/init_random_seed.h b/lib/init_random_seed.h
index aa9500514..01480338d 100644
--- a/lib/init_random_seed.h
+++ b/lib/init_random_seed.h
@@ -2,7 +2,7 @@
 #define INIT_RANDOM_SEED_H__
 
 #ifdef __cplusplus
-exten "C" {
+extern "C" {
 #endif
 
   /*
diff --git a/lib/jt4sim.f90 b/lib/jt4sim.f90
index 1950ce327..aabaee707 100644
--- a/lib/jt4sim.f90
+++ b/lib/jt4sim.f90
@@ -45,7 +45,8 @@ program jt4sim
   freq=f0                            !Silence compiler warning
   dphi=0.0                           !Silence compiler warning
 
-  call init_random_seed()
+  call init_random_seed(1)      ! seed Fortran RANDOM_NUMBER generator
+  call sgran()                  ! see C rand generator (used in gran)
 
   h=default_header(12000,npts)  
 
diff --git a/lib/jt65sim.f90 b/lib/jt65sim.f90
index 04f3ab62c..96f1331fa 100644
--- a/lib/jt65sim.f90
+++ b/lib/jt65sim.f90
@@ -35,7 +35,8 @@ program jt65sim
      go to 999
   endif
 
-  call init_random_seed(1)
+  call init_random_seed(1)      ! seed Fortran RANDOM_NUMBER generator
+  call sgran()                  ! see C rand generator (used in gran)
 
   csubmode='A'
   call getarg(1,csubmode)
diff --git a/lib/jt9sim.f90 b/lib/jt9sim.f90
index 29c775101..c9f4c7e79 100644
--- a/lib/jt9sim.f90
+++ b/lib/jt9sim.f90
@@ -67,6 +67,9 @@ program jt9sim
 !  if(minutes.eq.30) f0=1025.
 
 
+  call init_random_seed(1)      ! seed Fortran RANDOM_NUMBER generator
+  call sgran()                  ! see C rand generator (used in gran)
+
   h=default_header(12000,npts)  
   k=0                                !Silence compiler warning
 
diff --git a/lib/noisegen.f90 b/lib/noisegen.f90
index f92a9df01..333fc4696 100644
--- a/lib/noisegen.f90
+++ b/lib/noisegen.f90
@@ -2,6 +2,9 @@ subroutine noisegen(d4,nmax)
 
   real*4 d4(4,nmax)
 
+  call init_random_seed(1)      ! seed Fortran RANDOM_NUMBER generator
+  call sgran()                  ! see C rand generator (used in gran)
+
   do i=1,nmax
      d4(1,i)=gran()
      d4(2,i)=gran()
diff --git a/lib/sgran.c b/lib/sgran.c
index e3ac9a804..b48222e9b 100644
--- a/lib/sgran.c
+++ b/lib/sgran.c
@@ -1,8 +1,7 @@
 #include "init_random_seed.h"
 
-/* seed rand */
-float sgran_()
+/* Fortran wrapper to seed the C library rand */
+void sgran_(void)
 {
   init_random_seed();
-  return(0);
 }
diff --git a/lib/t1.f90 b/lib/t1.f90
index 97dc73ba1..ea2a636c4 100644
--- a/lib/t1.f90
+++ b/lib/t1.f90
@@ -23,7 +23,9 @@ program t1
   call getarg(3,arg)
   read(arg,*) iters
 
-  call init_random_seed()
+  call init_random_seed(1)      ! seed Fortran RANDOM_NUMBER generator
+  call sgran()                  ! see C rand generator (used in gran)
+
   call random_number(r)
   itone=0
   where(r.gt.0.5) itone=1
diff --git a/lib/timefft.f90 b/lib/timefft.f90
index 4e00838df..72ab41b2b 100644
--- a/lib/timefft.f90
+++ b/lib/timefft.f90
@@ -19,6 +19,8 @@ program timefft
   lthreading=maxthreads.ge.1
   maxthreads=max(1,maxthreads)
 
+  call sgran()                  ! see C rand generator (used in gran)
+
 ! Allocate data arrays
   pa=fftwf_alloc_complex(int(nfft,C_SIZE_T))
   call c_f_pointer(pa,a,[nfft])
diff --git a/main.cpp b/main.cpp
index 5ed5b2aa6..c388b09ff 100644
--- a/main.cpp
+++ b/main.cpp
@@ -28,6 +28,7 @@
 #include "SettingsGroup.hpp"
 #include "TraceFile.hpp"
 #include "mainwindow.h"
+#include "lib/init_random_seed.h"
 
 namespace
 {
@@ -44,6 +45,8 @@ namespace
 
 int main(int argc, char *argv[])
 {
+  init_random_seed ();
+
   register_types ();            // make the Qt magic happen
 
   // Multiple instances:
@@ -56,7 +59,7 @@ int main(int argc, char *argv[])
                                    // consistent format, do this after
                                    // instantiating QApplication so
                                    // that GUI has correct l18n
-	      
+
       // Override programs executable basename as application name.
       a.setApplicationName ("WSJT-X");
       a.setApplicationVersion (version ());