diff --git a/server/config-docs.ts b/server/config-docs.ts
index ecbaff1a87..5394442c30 100644
--- a/server/config-docs.ts
+++ b/server/config-docs.ts
@@ -344,6 +344,16 @@ export const loadConfig = (version: string) => {
     );
   }
 
+  const duplicateRedirects = checkDuplicateRedirects(config.redirects);
+  if (duplicateRedirects.length > 0) {
+    throw new Error(
+      "Error parsing docs config file " +
+        join("content", version, "docs", "config.json") +
+        ": Found redirects with duplicate sources: " +
+        JSON.stringify(duplicateRedirects, null, 2)
+    );
+  }
+
   validateConfig<Config>(validator, config);
 
   config.navigation.forEach((item, i) => {