diff --git a/lib/decoder.f90 b/lib/decoder.f90
index a9602260e..60653c105 100644
--- a/lib/decoder.f90
+++ b/lib/decoder.f90
@@ -122,7 +122,9 @@ subroutine decoder(ntrSeconds,ndepth,nRxLog,c00)
         ndecoded=1
      endif
   endif
-  ccfred(i-10:i+10)=0.
+  i1=max(ia,i-10)
+  i2=min(ib,i+10)
+  ccfred(i1:i2)=0.
   if(maxval(ccfred(ia:ib)).gt.3.0) go to 10
 
   if(fgood.eq.0.0) then
diff --git a/mainwindow.cpp b/mainwindow.cpp
index 1c3256d05..0679c75f8 100644
--- a/mainwindow.cpp
+++ b/mainwindow.cpp
@@ -1,4 +1,4 @@
-//------------------------------------------------------------- MainWindow
+//-------------------------------------------------------------- MainWindow
 #include "mainwindow.h"
 #include "ui_mainwindow.h"
 #include "devsetup.h"