diff --git a/lib/astrosub.f90 b/lib/astrosub.f90
index 0ca7b49cd..8e27a4a52 100644
--- a/lib/astrosub.f90
+++ b/lib/astrosub.f90
@@ -54,6 +54,12 @@ contains
          width1,width2,xlst8,techo8)
 
     if (len_trim(AzElFileName) .eq. 0) go to 999
+    if(len(trim(hisgrid)).eq.0) then  !If DX grid is blank, set these to zero:
+       AzMoonB8=0
+       ElMoonB8=0
+       ndop=0
+       width2=0
+    endif
     imin=60*uth8
     isec=3600*uth8
     ih=uth8
diff --git a/widgets/astro.cpp b/widgets/astro.cpp
index 6437c0721..d90a29ed3 100644
--- a/widgets/astro.cpp
+++ b/widgets/astro.cpp
@@ -121,12 +121,6 @@ auto Astro::astroUpdate(QDateTime const& t, QString const& mygrid, QString const
            AzElFileName.toLocal8Bit ().constData (),
            jpleph.toLocal8Bit ().constData ());
 
-    if(!hisgrid.size ()) {
-    azmoondx=0.0;
-    elmoondx=0.0;
-    m_dop=0;
-    width2=0.0;
-  }
   QString message;
   {
     QTextStream out {&message};