diff --git a/ts/src/transports/fetch.ts b/ts/src/transports/fetch.ts
index 230ba86a..d4c24104 100644
--- a/ts/src/transports/fetch.ts
+++ b/ts/src/transports/fetch.ts
@@ -44,6 +44,17 @@ class Fetch implements Transport {
         });
         this.pump(this.reader, res);
         return;
+      })
+      .catch(err => {
+        if (this.cancelled) {
+          this.options.debug && debug("Fetch.catch - request cancelled");
+          return;
+        }
+        this.cancelled = true;
+        this.options.debug && debug("Fetch.catch", err.message);
+        detach(() => {
+          this.options.onEnd(err);
+        });
       });
   }
 
@@ -69,6 +80,7 @@ class Fetch implements Transport {
         this.options.debug && debug("Fetch.catch - request cancelled");
         return;
       }
+      this.cancelled = true;
       this.options.debug && debug("Fetch.catch", err.message);
       detach(() => {
         this.options.onEnd(err);
@@ -89,6 +101,10 @@ class Fetch implements Transport {
   }
 
   cancel() {
+    if (this.cancelled) {
+      this.options.debug && debug("Fetch.abort.cancel already cancelled");
+      return;
+    }
     this.cancelled = true;
     if (this.reader) {
       // If the reader has already been received in the pump then it can be cancelled immediately