diff --git a/light-base/src/json_rpc_service/background.rs b/light-base/src/json_rpc_service/background.rs
index 8b7cade732..4d1b738927 100644
--- a/light-base/src/json_rpc_service/background.rs
+++ b/light-base/src/json_rpc_service/background.rs
@@ -1289,9 +1289,15 @@ impl<TPlat: PlatformRef> Background<TPlat> {
                 .apis
                 .find_version(api_name);
             match version {
-                None => return Err(RuntimeCallError::ApiNotFound),
+                None => {
+                    runtime_call_lock.unlock(virtual_machine);
+                    return Err(RuntimeCallError::ApiNotFound);
+                }
                 Some(v) if version_range.contains(&v) => Some(v),
-                Some(v) => return Err(RuntimeCallError::ApiVersionUnknown { actual_version: v }),
+                Some(v) => {
+                    runtime_call_lock.unlock(virtual_machine);
+                    return Err(RuntimeCallError::ApiVersionUnknown { actual_version: v });
+                }
             }
         } else {
             None
diff --git a/wasm-node/CHANGELOG.md b/wasm-node/CHANGELOG.md
index b98244fd81..84d06f805f 100644
--- a/wasm-node/CHANGELOG.md
+++ b/wasm-node/CHANGELOG.md
@@ -9,6 +9,7 @@
 ### Fixed
 
 - Fix panic when the best block of a chain switches to being equal to the current finalized block. This can occasionally happen for parachains in case of a reorg on the relay chain. ([#497](https://github.com/smol-dot/smoldot/pull/497))
+- Fix panic when failing to find the desired runtime API in a runtime. ([#512](https://github.com/smol-dot/smoldot/pull/512))
 
 ## 1.0.3 - 2023-04-27