diff --git a/docs/api-output.md b/docs/api-output.md
index fe8a8fe9..dd065b30 100644
--- a/docs/api-output.md
+++ b/docs/api-output.md
@@ -24,7 +24,9 @@ Returns **[Promise](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Refe
 # toBuffer
 
 Write output to a Buffer.
-By default, the format will match the input image. JPEG, PNG, WebP, and RAW are supported.
+JPEG, PNG, WebP, and RAW output are supported.
+By default, the format will match the input image, except GIF and SVG input which become PNG output.
+
 `callback`, if present, gets three arguments `(err, buffer, info)` where:
 
 -   `err` is an error message, if any.
diff --git a/docs/changelog.md b/docs/changelog.md
index 062c7118..b68325c8 100644
--- a/docs/changelog.md
+++ b/docs/changelog.md
@@ -15,6 +15,8 @@ Requires libvips v8.4.2.
   Access to these is now via output format functions, for example `quality(n)`
     is now `jpeg({quality: n})` and/or `webp({quality: n})`.
 
+* Autoconvert GIF and SVG input to PNG output if no other format is specified.
+
 * Expose libvips' "centre" resize option to mimic \*magick's +0.5px convention.
   [#568](https://github.com/lovell/sharp/issues/568)
 
diff --git a/lib/output.js b/lib/output.js
index ee498d3b..b164af75 100644
--- a/lib/output.js
+++ b/lib/output.js
@@ -45,7 +45,9 @@ const toFile = function toFile (fileOut, callback) {
 
 /**
  * Write output to a Buffer.
- * By default, the format will match the input image. JPEG, PNG, WebP, and RAW are supported.
+ * JPEG, PNG, WebP, and RAW output are supported.
+ * By default, the format will match the input image, except GIF and SVG input which become PNG output.
+ *
  * `callback`, if present, gets three arguments `(err, buffer, info)` where:
  * - `err` is an error message, if any.
  * - `buffer` is the output image data.
diff --git a/src/pipeline.cc b/src/pipeline.cc
index 83fee51b..06093d85 100644
--- a/src/pipeline.cc
+++ b/src/pipeline.cc
@@ -743,7 +743,8 @@ class PipelineWorker : public Nan::AsyncWorker {
           } else {
             baton->channels = std::min(baton->channels, 3);
           }
-        } else if (baton->formatOut == "png" || (baton->formatOut == "input" && inputImageType == ImageType::PNG)) {
+        } else if (baton->formatOut == "png" || (baton->formatOut == "input" &&
+          (inputImageType == ImageType::PNG || inputImageType == ImageType::GIF || inputImageType == ImageType::SVG))) {
           // Strip profile
           if (!baton->withMetadata) {
             vips_image_remove(image.get_image(), VIPS_META_ICC_NAME);
@@ -823,7 +824,8 @@ class PipelineWorker : public Nan::AsyncWorker {
           );
           baton->formatOut = "jpeg";
           baton->channels = std::min(baton->channels, 3);
-        } else if (baton->formatOut == "png" || isPng || (matchInput && inputImageType == ImageType::PNG)) {
+        } else if (baton->formatOut == "png" || isPng || (matchInput &&
+          (inputImageType == ImageType::PNG || inputImageType == ImageType::GIF || inputImageType == ImageType::SVG))) {
           // Strip profile
           if (!baton->withMetadata) {
             vips_image_remove(image.get_image(), VIPS_META_ICC_NAME);
diff --git a/test/unit/io.js b/test/unit/io.js
index cc63c39b..c46b872f 100644
--- a/test/unit/io.js
+++ b/test/unit/io.js
@@ -457,11 +457,16 @@ describe('Input/output', function () {
         });
     });
 
-    it('Match GIF input, therefore fail', function (done) {
+    it('Autoconvert GIF input to PNG output', function (done) {
       sharp(fixtures.inputGif)
         .resize(320, 80)
-        .toFile(fixtures.outputZoinks, function (err) {
-          assert(!!err);
+        .toFile(fixtures.outputZoinks, function (err, info) {
+          if (err) throw err;
+          assert.strictEqual(true, info.size > 0);
+          assert.strictEqual('png', info.format);
+          assert.strictEqual(320, info.width);
+          assert.strictEqual(80, info.height);
+          fs.unlinkSync(fixtures.outputZoinks);
           done();
         });
     });
@@ -696,9 +701,8 @@ describe('Input/output', function () {
       });
   });
 
-  it('Convert SVG with embedded images to PNG, respecting dimensions', function (done) {
+  it('Convert SVG with embedded images to PNG, respecting dimensions, autoconvert to PNG', function (done) {
     sharp(fixtures.inputSvgWithEmbeddedImages)
-      .png()
       .toBuffer(function (err, data, info) {
         if (err) throw err;
         assert.strictEqual('png', info.format);
@@ -772,10 +776,9 @@ describe('Input/output', function () {
       });
   });
 
-  it('Load GIF grey+alpha from file', function (done) {
+  it('Load GIF grey+alpha from file, auto convert to PNG', function (done) {
     sharp(fixtures.inputGifGreyPlusAlpha)
       .resize(8, 4)
-      .png()
       .toBuffer(function (err, data, info) {
         if (err) throw err;
         assert.strictEqual(true, data.length > 0);