diff --git a/lib/src/json_rpc/parse.rs b/lib/src/json_rpc/parse.rs
index d9e201bf26..b526b0be2c 100644
--- a/lib/src/json_rpc/parse.rs
+++ b/lib/src/json_rpc/parse.rs
@@ -289,7 +289,7 @@ pub fn build_error_response(
             (SerdeErrorCode::ServerError(n), msg)
         }
         ErrorResponse::ApplicationDefined(n, msg) => {
-            assert!(!(-32700..=-32000).contains(&n));
+            assert!(!(-32768..=-32000).contains(&n));
             (SerdeErrorCode::MethodError(n), msg)
         }
     };
diff --git a/light-base/src/json_rpc_service/background/chain_head.rs b/light-base/src/json_rpc_service/background/chain_head.rs
index 7d254d2622..1ad7202422 100644
--- a/light-base/src/json_rpc_service/background/chain_head.rs
+++ b/light-base/src/json_rpc_service/background/chain_head.rs
@@ -98,7 +98,7 @@ impl<TPlat: PlatformRef> Background<TPlat> {
                     "Rejected `chainHead_unstable_follow` subscription due to limit reached."
                 );
                 request.fail(json_rpc::parse::ErrorResponse::ApplicationDefined(
-                    -32100,
+                    -32800,
                     "Maximum number of `chainHead_unstable_follow` subscriptions reached",
                 ));
                 return;
diff --git a/wasm-node/CHANGELOG.md b/wasm-node/CHANGELOG.md
index 69a18e934a..85b2577551 100644
--- a/wasm-node/CHANGELOG.md
+++ b/wasm-node/CHANGELOG.md
@@ -11,6 +11,7 @@
 
 - Fix panic when the runtime of a chain provides consensus information that is inconsistent with the information found in the finalized block. ([#1317](https://github.com/smol-dot/smoldot/pull/1317))
 - Incoming notification substreams are now properly when accepted when a peer doesn't have a slot or gets a slot later on. ([#1369](https://github.com/smol-dot/smoldot/pull/1369))
+- Fix panic when `chainHead_unstable_follow` is called too many times. ([#1392](https://github.com/smol-dot/smoldot/pull/1392))
 
 ## 2.0.10 - 2023-11-17