diff --git a/src/pipeline.cc b/src/pipeline.cc
index b640bddb7..bcc577081 100644
--- a/src/pipeline.cc
+++ b/src/pipeline.cc
@@ -298,10 +298,13 @@ class PipelineWorker : public Napi::AsyncWorker {
       if (baton->input->autoOrient) {
         image = sharp::RemoveExifOrientation(image);
       }
+      VImage gainMapSource;
       VImage gainMap;
       int gainMapScaleFactor = 1;
       if (sharp::HasGainMap(image)) {
         if (baton->keepGainMap) {
+          // Keep source-owned gain-map bytes alive for lazy decoding.
+          gainMapSource = image;
           gainMap = image.gainmap();
           if (image.get_typeof("gainmap-scale-factor") == G_TYPE_INT) {
             gainMapScaleFactor = image.get_int("gainmap-scale-factor");
diff --git a/test/unit/gain-map.js b/test/unit/gain-map.js
index 17751522b..9a393616d 100644
--- a/test/unit/gain-map.js
+++ b/test/unit/gain-map.js
@@ -10,6 +10,31 @@ const sharp = require('../../');
 const fixtures = require('../fixtures');
 
 suite('Gain maps', () => {
+  test('Can rotate while keeping gain map with cache disabled', async (t) => {
+    const previousCache = sharp.cache();
+    sharp.cache(false);
+    try {
+      const data = await sharp(fixtures.inputJpgWithGainMap)
+        .keepGainMap()
+        .rotate(90)
+        .toBuffer();
+      const metadata = await sharp(data).metadata();
+      t.assert.deepStrictEqual([metadata.width, metadata.height], [2160, 3840]);
+      t.assert.ok(metadata.gainMap);
+      const { data: gainMapPixels, info: gainMapInfo } = await sharp(metadata.gainMap.image)
+        .raw()
+        .toBuffer({ resolveWithObject: true });
+      t.assert.ok(gainMapPixels.length > 0);
+      t.assert.deepStrictEqual([gainMapInfo.width, gainMapInfo.height], [540, 960]);
+    } finally {
+      sharp.cache({
+        memory: previousCache.memory.max,
+        files: previousCache.files.max,
+        items: previousCache.items.max
+      });
+    }
+  });
+
   test('Metadata contains gainMap', async (t) => {
     t.plan(4);