diff --git a/http/bin/gmi2upphtml b/http/bin/gmi2upphtml
index b43693d..1631037 100755
--- a/http/bin/gmi2upphtml
+++ b/http/bin/gmi2upphtml
@@ -53,7 +53,14 @@ close_all_open_blocks()
 
 escape_upphtml()
 {
-  echo "$1" | sed "s/\`/\\\\\`/g" | sed "s/\"/\\\\\"/g" | sed "s/\\\$/\\\\\$/g"
+  echo "$1" \
+    | sed "s/&/\\&/g" \
+    | sed "s/</\\&lt;/g" \
+    | sed "s/>/\\&gt;/g" \
+    | sed "s/\"/\\&quot;/g" \
+    | sed "s/'/\\&#x27;/g" \
+    | sed "s/\`/\\&#x60;/g" \
+    | sed "s/\\\$/\\\\\$/g"
 }
 
 close_all_open_blocks_except()