diff --git a/packages/docusaurus-plugin-openapi-docs/src/index.ts b/packages/docusaurus-plugin-openapi-docs/src/index.ts
index 8c4311561..bfd79cd71 100644
--- a/packages/docusaurus-plugin-openapi-docs/src/index.ts
+++ b/packages/docusaurus-plugin-openapi-docs/src/index.ts
@@ -353,9 +353,18 @@ custom_edit_url: null
                 .toString("base64"));
           let infoBasePath = `${outputDir}/${item.infoId}`;
           if (docRouteBasePath) {
-            infoBasePath = `${docRouteBasePath}/${outputDir
-              .split(docPath!)[1]
-              .replace(/^\/+/g, "")}/${item.infoId}`.replace(/^\/+/g, "");
+            // Safely extract path segment, handling cases where docPath may not be in outputDir
+            const outputSegment =
+              docPath && outputDir.includes(docPath)
+                ? (outputDir.split(docPath)[1]?.replace(/^\/+/g, "") ?? "")
+                : outputDir
+                    .slice(outputDir.indexOf("/", 1))
+                    .replace(/^\/+/g, "");
+            infoBasePath =
+              `${docRouteBasePath}/${outputSegment}/${item.infoId}`.replace(
+                /^\/+/g,
+                ""
+              );
           }
           if (item.infoId) item.infoPath = infoBasePath;
         }
diff --git a/packages/docusaurus-plugin-openapi-docs/src/sidebars/index.ts b/packages/docusaurus-plugin-openapi-docs/src/sidebars/index.ts
index 8e2670e40..1f7376f81 100644
--- a/packages/docusaurus-plugin-openapi-docs/src/sidebars/index.ts
+++ b/packages/docusaurus-plugin-openapi-docs/src/sidebars/index.ts
@@ -125,9 +125,21 @@ function groupByTags(
     apiTags = uniq(apiTags.concat(operationTags, schemaTags));
   }
 
-  const basePath = docPath
-    ? outputDir.split(docPath!)[1].replace(/^\/+/g, "")
-    : outputDir.slice(outputDir.indexOf("/", 1)).replace(/^\/+/g, "");
+  // Extract base path from outputDir, handling cases where docPath may not be in outputDir
+  const getBasePathFromOutput = (
+    output: string,
+    doc: string | undefined
+  ): string => {
+    if (doc && output.includes(doc)) {
+      return output.split(doc)[1]?.replace(/^\/+/g, "") ?? "";
+    }
+    const slashIndex = output.indexOf("/", 1);
+    return slashIndex === -1
+      ? ""
+      : output.slice(slashIndex).replace(/^\/+/g, "");
+  };
+
+  const basePath = getBasePathFromOutput(outputDir, docPath);
 
   const createDocItemFnContext = {
     sidebarOptions,