diff --git a/ezjail-admin b/ezjail-admin
index 4acb4c2..15c2a70 100755
--- a/ezjail-admin
+++ b/ezjail-admin
@@ -223,10 +223,20 @@ update)
     echo "Cannot find your copy of the FreeBSD source tree in $ezjail_sourcetree."; exit 1;
   fi
 
+  if [ ! -f ${ezjail_sourcetree}/Makefile ]; then
+    echo "Your source tree in $ezjail_sourcetree seems to be incomplete (Makefile missing)."; exit 1;
+  fi
+
   cd ${ezjail_sourcetree}
   rm -rf ${ezjail_jailfull}; mkdir -p ${ezjail_jailfull}
   make ${updatejail_installaction} DESTDIR=${ezjail_jailfull}
+  if [ $? != 0 ]; then
+    echo "make ${updatejail_installaction} failed"; exit 1;
+  fi
   make distribution DESTDIR=${ezjail_jailfull}
+  if [ $? != 0 ]; then
+    echo "make distribution failed"; exit 1;
+  fi
 
   cd ${ezjail_jailfull}
   mkdir -p ${ezjail_jailbase}/usr ${ezjail_jailbase}/config/pkg