diff --git a/.changeset/loud-ties-beg.md b/.changeset/loud-ties-beg.md
new file mode 100644
index 000000000..17ce213b0
--- /dev/null
+++ b/.changeset/loud-ties-beg.md
@@ -0,0 +1,5 @@
+---
+"@browserbasehq/stagehand": patch
+---
+
+Temporarily patch custom clients serialization error on api
diff --git a/lib/index.ts b/lib/index.ts
index 8e534ed87..786958ff1 100644
--- a/lib/index.ts
+++ b/lib/index.ts
@@ -614,6 +614,13 @@ export class Stagehand {
 
     if (llmClient) {
       this.llmClient = llmClient;
+      this.logger({
+        category: "init",
+        message:
+          "Custom LLM clients are currently not supported in API mode",
+        level: 1,
+      });
+      this.usingAPI = false;
     } else {
       try {
         // try to set a default LLM client