diff --git a/web/src/lib/oidc.ts b/web/src/lib/oidc.ts
index 779736c..87633ed 100644
--- a/web/src/lib/oidc.ts
+++ b/web/src/lib/oidc.ts
@@ -77,7 +77,7 @@ export async function startLogin(): Promise<void> {
   sessionStorage.setItem(PKCE_KEY, codeVerifier)
   sessionStorage.setItem(STATE_KEY, oidcState)
 
-  const redirectURI = location.origin + location.pathname
+  const redirectURI = (location.origin + location.pathname).replace(/\/$/, '')
 
   const params = new URLSearchParams({
     response_type: 'code',
@@ -103,7 +103,7 @@ export async function handleCallback(code: string, returnedState: string): Promi
   const cfg = state.config ?? await fetchConfig()
   if (!cfg) return false
 
-  const redirectURI = location.origin + location.pathname
+  const redirectURI = (location.origin + location.pathname).replace(/\/$/, '')
 
   try {
     const resp = await fetch(apiBase('/api/v1/auth/oidc-token'), {