diff --git a/lib/Internal/EmitSource.php b/lib/Internal/EmitSource.php
index 0029d97..f924136 100644
--- a/lib/Internal/EmitSource.php
+++ b/lib/Internal/EmitSource.php
@@ -226,6 +226,14 @@ final class EmitSource
         return $this->completed;
     }
 
+    /**
+     * @return bool True if the stream was disposed.
+     */
+    public function isDisposed(): bool
+    {
+        return $this->disposed;
+    }
+
     /**
      * Completes the stream.
      **
diff --git a/lib/StreamSource.php b/lib/StreamSource.php
index e2ca679..a0fc62f 100644
--- a/lib/StreamSource.php
+++ b/lib/StreamSource.php
@@ -56,6 +56,14 @@ final class StreamSource
         return $this->source->isComplete();
     }
 
+    /**
+     * @return bool True if the stream has been disposed.
+     */
+    public function isDisposed(): bool
+    {
+        return $this->source->isDisposed();
+    }
+
     /**
      * Completes the stream.
      *
diff --git a/test/StreamSourceTest.php b/test/StreamSourceTest.php
index 7e72635..136942b 100644
--- a/test/StreamSourceTest.php
+++ b/test/StreamSourceTest.php
@@ -213,6 +213,7 @@ class StreamSourceTest extends AsyncTestCase
         $stream = $this->source->stream();
         $promise = $this->source->emit(1);
         $stream->dispose();
+        $this->assertTrue($this->source->isDisposed());
         $this->assertNull(yield $promise);
         yield $this->source->emit(1);
     }
@@ -226,6 +227,7 @@ class StreamSourceTest extends AsyncTestCase
         $stream = $this->source->stream();
         $promise = $this->source->emit(1);
         unset($stream);
+        $this->assertTrue($this->source->isDisposed());
         $this->assertNull(yield $promise);
         yield $this->source->emit(1);
     }