diff --git a/front/src/WebRtc/HtmlUtils.ts b/front/src/WebRtc/HtmlUtils.ts
index 81f069b3..168fba1e 100644
--- a/front/src/WebRtc/HtmlUtils.ts
+++ b/front/src/WebRtc/HtmlUtils.ts
@@ -1,21 +1,19 @@
 export class HtmlUtils {
     public static getElementByIdOrFail<T extends HTMLElement>(id: string): T {
         const elem = document.getElementById(id);
-        if (elem === null) {
-            throw new Error("Cannot find HTML element with id '"+id+"'");
+        if (HtmlUtils.isHtmlElement<T>(elem)) {
+           return elem;
         }
-        // FIXME: does not check the type of the returned type
-        return elem as T;
+        throw new Error("Cannot find HTML element with id '"+id+"'");
     }
 
     public static removeElementByIdOrFail<T extends HTMLElement>(id: string): T {
         const elem = document.getElementById(id);
-        if (elem === null) {
-            throw new Error("Cannot find HTML element with id '"+id+"'");
+        if (HtmlUtils.isHtmlElement<T>(elem)) {
+            elem.remove();
+            return elem;
         }
-        // FIXME: does not check the type of the returned type
-        elem.remove();
-        return elem as T;
+        throw new Error("Cannot find HTML element with id '"+id+"'");
     }
 
     public static urlify(text: string): string {
@@ -24,4 +22,8 @@ export class HtmlUtils {
             return '<a href="' + url + '" target="_blank" style=":visited {color: white}">' + url + '</a>';
         })
     }
+
+    private static isHtmlElement<T extends HTMLElement>(elem: HTMLElement | null): elem is T {
+        return elem !== null;
+    }
 }