diff --git a/.changeset/fix-webdriverio-peer-to-dep.md b/.changeset/fix-webdriverio-peer-to-dep.md
new file mode 100644
index 0000000..58cbe97
--- /dev/null
+++ b/.changeset/fix-webdriverio-peer-to-dep.md
@@ -0,0 +1,5 @@
+---
+"@wdio/browserstack-service": patch
+---
+
+Declare `webdriverio` as a dependency instead of a peerDependency, matching the package published from the WebdriverIO monorepo. The extraction had moved `webdriverio` into `peerDependencies` (`^9.0.0`); npm then forced the consumer's `webdriverio` to `^9`, which conflicts with any project that also depends on a package peering `webdriverio@"^7 || ^8"` (e.g. `wdio-chromedriver-service@^8`) and surfaced as an `npm ERESOLVE` on install — a failure the monorepo-published package never had. Restores install parity with the upstream package; no user-facing API change.
diff --git a/package-lock.json b/package-lock.json
index d5d0c49..b8d072b 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -12916,6 +12916,7 @@
         "tar": "^7.5.11",
         "undici": "^6.24.0",
         "uuid": "^11.1.0",
+        "webdriverio": "^9.0.0",
         "winston-transport": "^4.5.0",
         "yauzl": "^3.4.0"
       },
@@ -12940,8 +12941,7 @@
         "node": ">=18.20.0"
       },
       "peerDependencies": {
-        "@wdio/cli": "^5.0.0 || ^6.0.0 || ^7.0.0 || ^8.0.0 || ^9.0.0",
-        "webdriverio": "^9.0.0"
+        "@wdio/cli": "^5.0.0 || ^6.0.0 || ^7.0.0 || ^8.0.0 || ^9.0.0"
       }
     },
     "packages/browserstack-service/node_modules/@esbuild/aix-ppc64": {
diff --git a/packages/browserstack-service/package.json b/packages/browserstack-service/package.json
index a60a597..8008d6b 100644
--- a/packages/browserstack-service/package.json
+++ b/packages/browserstack-service/package.json
@@ -72,11 +72,11 @@
     "yauzl": "^3.4.0",
     "@wdio/logger": "^9.0.0",
     "@wdio/reporter": "^9.0.0",
-    "@wdio/types": "^9.0.0"
+    "@wdio/types": "^9.0.0",
+    "webdriverio": "^9.0.0"
   },
   "peerDependencies": {
-    "@wdio/cli": "^5.0.0 || ^6.0.0 || ^7.0.0 || ^8.0.0 || ^9.0.0",
-    "webdriverio": "^9.0.0"
+    "@wdio/cli": "^5.0.0 || ^6.0.0 || ^7.0.0 || ^8.0.0 || ^9.0.0"
   },
   "devDependencies": {
     "@bufbuild/buf": "^1.55.1",