diff --git a/src/browser-installer/registry/index.ts b/src/browser-installer/registry/index.ts
index c94211d8c..e5b600e04 100644
--- a/src/browser-installer/registry/index.ts
+++ b/src/browser-installer/registry/index.ts
@@ -159,6 +159,8 @@ export const getMatchedBrowserVersion = (
         a = a.slice(a.indexOf("_") + 1);
         b = b.slice(b.indexOf("_") + 1);
 
+        // Firefox has versions like "stable_131.0a1" and "stable_129.0b9"
+        // Parsing raw numbers as hex values is needed in order to distinguish "129.0b9" and "129.0b7" for example
         return parseInt(a.replace(".", ""), 16) - parseInt(b.replace(".", ""), 16);
     };
 
diff --git a/src/browser-installer/run.ts b/src/browser-installer/run.ts
index 71c442b13..9e3adc45c 100644
--- a/src/browser-installer/run.ts
+++ b/src/browser-installer/run.ts
@@ -15,5 +15,7 @@ export const runBrowserDriver = async (
             return import("./firefox").then(module => module.runGeckoDriver(browserVersion, { debug }));
         case Driver.SAFARIDRIVER:
             return import("./safari").then(module => module.runSafariDriver({ debug }));
+        default:
+            throw new Error(`Invalid driver name: ${driverName}. Expected one of: ${Object.values(Driver).join(", ")}`);
     }
 };
diff --git a/src/browser-pool/webdriver-pool.ts b/src/browser-pool/webdriver-pool.ts
index 413abdfd2..715acb6b3 100644
--- a/src/browser-pool/webdriver-pool.ts
+++ b/src/browser-pool/webdriver-pool.ts
@@ -32,6 +32,10 @@ export class WebdriverPool {
             );
         }
 
+        if (!browserVersion) {
+            throw new Error(`Couldn't run browser driver for "${browserName}" because its version is undefined`);
+        }
+
         const wdProcesses = this.driverProcess.get(driverName)?.get(browserVersion) ?? {};
 
         for (const port in wdProcesses) {