diff --git a/app/client/models/AdminChecks.ts b/app/client/models/AdminChecks.ts
index bd5a8cee..bbea371b 100644
--- a/app/client/models/AdminChecks.ts
+++ b/app/client/models/AdminChecks.ts
@@ -53,7 +53,7 @@ export class AdminChecks {
     const {id} = probe;
     let result = this._results.get(id);
     if (!result) {
-      result = Observable.create(this._parent, {});
+      result = Observable.create(this._parent, {status: 'none'});
       this._results.set(id, result);
     }
     let request = this._requests.get(id);
@@ -108,7 +108,7 @@ export class AdminCheckRunner {
   public start() {
     let result = this.results.get(this.id);
     if (!result) {
-      result = Observable.create(this.parent, {});
+      result = Observable.create(this.parent, {status: 'none'});
       this.results.set(this.id, result);
     }
   }
diff --git a/app/client/ui/AdminPanel.ts b/app/client/ui/AdminPanel.ts
index 48703444..dfecb1ff 100644
--- a/app/client/ui/AdminPanel.ts
+++ b/app/client/ui/AdminPanel.ts
@@ -179,7 +179,7 @@ Please log in as an administrator.`)),
       use => {
         const req = this._checks.requestCheckById(use, 'sandboxing');
         const result = req ? use(req.result) : undefined;
-        const success = result?.success;
+        const success = result?.status === 'success';
         const details = result?.details as SandboxingBootProbeDetails|undefined;
         if (!details) {
           return cssValueLabel(t('unknown'));
@@ -217,7 +217,8 @@ Please log in as an administrator.`)),
           return cssValueLabel(cssErrorText('unavailable'));
         }
 
-        const { success, details } = result;
+        const { status, details } = result;
+        const success = status === 'success';
         const loginSystemId = details?.loginSystemId;
 
         if (!success || !loginSystemId) {
@@ -500,10 +501,10 @@ Please log in as an administrator.`)),
           { style: 'margin-top: 0px; padding-top: 0px;' },
         ),
         result.verdict ? dom('pre', result.verdict) : null,
-        (result.success === undefined) ? null :
+        (result.status === 'none') ? null :
             dom('p',
-                result.success ? t('Check succeeded.') : t('Check failed.')),
-        (result.done !== true) ? null :
+                (result.status === 'success') ? t('Check succeeded.') : t('Check failed.')),
+        (result.status !== 'none') ? null :
             dom('p', t('No fault detected.')),
         (details?.info === undefined) ? null : [
           cssCheckHeader(t('Notes')),
@@ -530,12 +531,21 @@ Please log in as an administrator.`)),
    * visualization of the results can be elaborated in future.
    */
   private _encodeSuccess(result: BootProbeResult) {
-    if (result.success === undefined)  { return '―';  }
-    if (result.success)                { return '✅'; }
-    if (result.severity === 'warning') { return '❗';  }
-    if (result.severity === 'hmm') { return '?';  }
-    // remaining case is a fault.
-    return '❌';
+    switch (result.status) {
+      case 'success':
+        return '✅';
+      case 'fault':
+        return '❌';
+      case 'warning':
+        return '❗';
+      case 'hmm':
+        return '?';
+      case 'none':
+        return '―';
+      default:
+        // should not arrive here
+        return '??';
+    }
   }
 }
 
diff --git a/app/common/BootProbe.ts b/app/common/BootProbe.ts
index 0da3c859..49fb9911 100644
--- a/app/common/BootProbe.ts
+++ b/app/common/BootProbe.ts
@@ -13,9 +13,12 @@ export type BootProbeIds =
 
 export interface BootProbeResult {
   verdict?: string;
-  success?: boolean;
-  done?: boolean;
-  severity?: 'fault' | 'warning' | 'hmm';
+  // Result of check.
+  // "success" is a positive outcome.
+  // "none" means no fault detected (but that the test is not exhaustive
+  // enough to claim "success").
+  // "fault" is a bad error, "warning" a ... warning, "hmm" almost a debug message.
+  status: 'success' | 'fault' | 'warning' | 'hmm' | 'none';
   details?: Record<string, any>;
 }
 
diff --git a/app/server/lib/BootProbes.ts b/app/server/lib/BootProbes.ts
index 8145f2a2..df9427f2 100644
--- a/app/server/lib/BootProbes.ts
+++ b/app/server/lib/BootProbes.ts
@@ -91,17 +91,16 @@ const _homeUrlReachableProbe: Probe = {
         throw new ApiError(await resp.text(), resp.status);
       }
       return {
-        success: true,
+        status: 'success',
         details,
       };
     } catch (e) {
       return {
-        success: false,
         details: {
           ...details,
           error: String(e),
         },
-        severity: 'fault',
+        status: 'fault',
       };
     }
   }
@@ -121,7 +120,7 @@ const _webSocketsProbe: Probe = {
       ws.on('open', () => {
         ws.send('Just nod if you can hear me.');
         resolve({
-          success: true,
+          status: 'success',
           details,
         });
         ws.close();
@@ -129,7 +128,7 @@ const _webSocketsProbe: Probe = {
       ws.on('error', (ev) => {
         details.error = ev.message;
         resolve({
-          success: false,
+          status: 'fault',
           details,
         });
         ws.close();
@@ -159,17 +158,16 @@ const _statusCheckProbe: Probe = {
         throw new Error(`Failed, page has unexpected content`);
       }
       return {
-        success: true,
+        status: 'success',
         details,
       };
     } catch (e) {
       return {
-        success: false,
         details: {
           ...details,
           error: String(e),
         },
-        severity: 'fault',
+        status: 'fault',
       };
     }
   },
@@ -185,13 +183,12 @@ const _userProbe: Probe = {
     if (process.getuid && process.getuid() === 0) {
       return {
         details,
-        success: false,
         verdict: 'User appears to be root (UID 0)',
-        severity: 'warning',
+        status: 'warning',
       };
     } else {
       return {
-        success: true,
+        status: 'success',
         details,
       };
     }
@@ -208,22 +205,20 @@ const _bootProbe: Probe = {
       bootKeySet: hasBoot,
     };
     if (!hasBoot) {
-      return { success: true, details };
+      return { status: 'success', details };
     }
     details.bootKeyLength = bootKey.length;
     if (bootKey.length < 10) {
       return {
-        success: false,
         verdict: 'Boot key length is shorter than 10.',
         details,
-        severity: 'fault',
+        status: 'fault',
       };
     }
     return {
-      success: false,
       verdict: 'Boot key ideally should be removed after installation.',
       details,
-      severity: 'warning',
+      status: 'warning',
     };
   },
 };
@@ -247,19 +242,18 @@ const _hostHeaderProbe: Probe = {
     };
     if (url.hostname === 'localhost') {
       return {
-        done: true,
+        status: 'none',
         details,
       };
     }
     if (String(url.hostname).toLowerCase() !== String(host).toLowerCase()) {
       return {
-        success: false,
         details,
-        severity: 'hmm',
+        status: 'hmm',
       };
     }
     return {
-      done: true,
+      status: 'none',
       details,
     };
   },
@@ -271,7 +265,7 @@ const _sandboxingProbe: Probe = {
   apply: async (server, req) => {
     const details = server.getSandboxInfo();
     return {
-      success: details?.configured && details?.functional,
+      status: (details?.configured && details?.functional) ? 'success' : 'fault',
       details,
     };
   },
@@ -283,7 +277,7 @@ const _authenticationProbe: Probe = {
   apply: async(server, req) => {
     const loginSystemId = server.getInfo('loginMiddlewareComment');
     return {
-      success: loginSystemId != undefined,
+      status: (loginSystemId != undefined) ? 'success' : 'fault',
       details: {
         loginSystemId,
       }