diff --git a/src/pipeline/pipeline.ts b/src/pipeline/pipeline.ts
index f4fac697..1f621ccc 100644
--- a/src/pipeline/pipeline.ts
+++ b/src/pipeline/pipeline.ts
@@ -95,11 +95,14 @@ class Pipeline<T, P = {}> extends EventEmitter<PipelineEvents<T>> {
     if (!processor) return;
 
     const subSteps = this._steps.get(processor.type);
-    this._steps.set(
-      processor.type,
-      subSteps.filter((proc) => proc != processor),
-    );
-    this.emit('updated', processor);
+
+    if (subSteps && subSteps.length) {
+      this._steps.set(
+        processor.type,
+        subSteps.filter((proc) => proc != processor),
+      );
+      this.emit('updated', processor);
+    }
   }
 
   /**
diff --git a/tests/pipeline/pipeline.test.ts b/tests/pipeline/pipeline.test.ts
index 3ccf06e1..8df1ad37 100644
--- a/tests/pipeline/pipeline.test.ts
+++ b/tests/pipeline/pipeline.test.ts
@@ -70,6 +70,8 @@ describe('Pipeline', () => {
     expect(pipeline.steps).toHaveLength(1);
     pipeline.unregister(null);
     expect(pipeline.steps).toHaveLength(1);
+    pipeline.unregister(new NoopProcessor());
+    expect(pipeline.steps).toHaveLength(1);
     pipeline.unregister(proc);
     expect(pipeline.steps).toHaveLength(0);
   });