diff --git a/src/session-pool.ts b/src/session-pool.ts
index a6ba7b601..1d55da60f 100644
--- a/src/session-pool.ts
+++ b/src/session-pool.ts
@@ -184,12 +184,26 @@ export class SessionLeakError extends Error {
   }
 }
 
+/**
+ * Error to be thrown when the session pool is exhausted.
+ */
+export class SessionPoolExhaustedError extends Error {
+  messages: string[];
+  constructor(leaks: string[]) {
+    super(errors.Exhausted);
+    // Restore error name that was overwritten by the super constructor call.
+    this.name = SessionPoolExhaustedError.name;
+    this.messages = leaks;
+  }
+}
+
 /**
  * enum to capture errors that can appear from multiple places
  */
 const enum errors {
   Closed = 'Database is closed.',
   Timeout = 'Timeout occurred while acquiring session.',
+  Exhausted = 'No resources available.',
 }
 
 interface SessionInventory {
@@ -723,8 +737,8 @@ export class SessionPool extends EventEmitter implements SessionPoolInterface {
       return this._borrowNextAvailableSession(type);
     }
 
-    if (this.options.fail!) {
-      throw new Error('No resources available.');
+    if (this.isFull && this.options.fail!) {
+      throw new SessionPoolExhaustedError(this._getLeaks());
     }
 
     let removeListener: Function;