diff --git a/html5/js/Client.js b/html5/js/Client.js
index 3fe0fe53..79780e3f 100644
--- a/html5/js/Client.js
+++ b/html5/js/Client.js
@@ -3242,7 +3242,7 @@ class XpraClient {
 
   reconfigure_all_trays() {
     const float_menu = document.querySelector(FLOAT_MENU_SELECTOR);
-    float_menu_width = float_menu_item_size * 4 + float_menu_padding;
+    let float_menu_width = float_menu_item_size * 4 + float_menu_padding;
     for (const twid in this.id_to_window) {
       const twin = this.id_to_window[twid];
       if (twin && twin.tray) {
diff --git a/html5/js/Keycodes.js b/html5/js/Keycodes.js
index d1b7b0f8..ce3c809c 100644
--- a/html5/js/Keycodes.js
+++ b/html5/js/Keycodes.js
@@ -9,7 +9,7 @@
 /**
  * Map javascript key names to the X11 naming convention the server expects:
  */
-KEY_TO_NAME = {
+const KEY_TO_NAME = {
   Escape: "Escape",
   Tab: "Tab",
   CapsLock: "Caps_Lock",
@@ -37,11 +37,11 @@ KEY_TO_NAME = {
   End: "End",
   PageDown: "Next",
 };
-DEAD_KEYS = {
+const DEAD_KEYS = {
   "`": "dead_grave",
   "'": "dead_acute",
 };
-NUMPAD_TO_NAME = {
+const NUMPAD_TO_NAME = {
   //Num pad:
   NumpadDivide: "KP_Divide",
   NumpadMultiply: "KP_Multiply",
@@ -76,7 +76,7 @@ for (let index = 1; index <= 20; index++) {
  * 		sed 's/#define XKB_KEY_//g; s/ *0x.*U+/ 0x/g' | \
  * 		awk '{print "\""$1"\" : "$2","}'
  */
-KEYSYM_TO_UNICODE = {
+const KEYSYM_TO_UNICODE = {
   space: 0x00_20,
   exclam: 0x00_21,
   quotedbl: 0x00_22,
@@ -1622,7 +1622,7 @@ KEYSYM_TO_UNICODE = {
   Sinh_kunddaliya: 0x0d_f4,
 };
 
-CHAR_TO_NAME = {
+const CHAR_TO_NAME = {
   " ": "space",
 };
 for (const keysym in KEYSYM_TO_UNICODE) {
@@ -1632,7 +1632,7 @@ for (const keysym in KEYSYM_TO_UNICODE) {
 }
 
 //some keysyms require specific layouts
-KEYSYM_TO_LAYOUT = {
+const KEYSYM_TO_LAYOUT = {
   kana: "jp",
   Farsi: "ir",
   Arabic: "ar",
@@ -1652,7 +1652,7 @@ KEYSYM_TO_LAYOUT = {
  *
  * TODO: some values are missing..
  */
-CHARCODE_TO_NAME = {
+const CHARCODE_TO_NAME = {
   8: "BackSpace",
   9: "Tab",
   12: "KP_Begin",