diff --git a/docs/src/content/docs/changelog/v0.34.5.md b/docs/src/content/docs/changelog/v0.34.5.md
index a754c33a..886932b8 100644
--- a/docs/src/content/docs/changelog/v0.34.5.md
+++ b/docs/src/content/docs/changelog/v0.34.5.md
@@ -9,3 +9,6 @@ slug: changelog/v0.34.5
 * Add support for BigTIFF output.
   [#4459](https://github.com/lovell/sharp/pull/4459)
   [@throwbi](https://github.com/throwbi)
+
+* Improve error messaging when only warnings issued.
+  [#4465](https://github.com/lovell/sharp/issues/4465)
diff --git a/src/pipeline.cc b/src/pipeline.cc
index 2b952fc9..4a848293 100644
--- a/src/pipeline.cc
+++ b/src/pipeline.cc
@@ -1278,7 +1278,12 @@ class PipelineWorker : public Napi::AsyncWorker {
       if (what && what[0]) {
         (baton->err).append(what);
       } else {
-        (baton->err).append("Unknown error");
+        if (baton->input->failOn == VIPS_FAIL_ON_WARNING) {
+          (baton->err).append("Warning treated as error due to failOn setting");
+          baton->errUseWarning = true;
+        } else {
+          (baton->err).append("Unknown error");
+        }
       }
     }
     // Clean up libvips' per-request data and threads
@@ -1293,7 +1298,11 @@ class PipelineWorker : public Napi::AsyncWorker {
     // Handle warnings
     std::string warning = sharp::VipsWarningPop();
     while (!warning.empty()) {
-      debuglog.Call(Receiver().Value(), { Napi::String::New(env, warning) });
+      if (baton->errUseWarning) {
+        (baton->err).append("\n").append(warning);
+      } else {
+        debuglog.Call(Receiver().Value(), { Napi::String::New(env, warning) });
+      }
       warning = sharp::VipsWarningPop();
     }
 
diff --git a/src/pipeline.h b/src/pipeline.h
index eaec71fa..14ee5456 100644
--- a/src/pipeline.h
+++ b/src/pipeline.h
@@ -198,6 +198,7 @@ struct PipelineBaton {
   bool jxlLossless;
   VipsBandFormat rawDepth;
   std::string err;
+  bool errUseWarning;
   int keepMetadata;
   int withMetadataOrientation;
   double withMetadataDensity;
@@ -373,6 +374,7 @@ struct PipelineBaton {
     jxlEffort(7),
     jxlLossless(false),
     rawDepth(VIPS_FORMAT_UCHAR),
+    errUseWarning(false),
     keepMetadata(0),
     withMetadataOrientation(-1),
     withMetadataDensity(0.0),
diff --git a/test/fixtures/bonne.geo.tif b/test/fixtures/bonne.geo.tif
new file mode 100644
index 00000000..1592bf86
Binary files /dev/null and b/test/fixtures/bonne.geo.tif differ
diff --git a/test/fixtures/index.js b/test/fixtures/index.js
index 153eb37b..b5714875 100644
--- a/test/fixtures/index.js
+++ b/test/fixtures/index.js
@@ -113,6 +113,7 @@ module.exports = {
   inputTiff8BitDepth: getPath('8bit_depth.tiff'),
   inputTifftagPhotoshop: getPath('tifftag-photoshop.tiff'), // https://github.com/lovell/sharp/issues/1600
   inputTiffFogra: getPath('fogra-0-100-100-0.tif'), // https://github.com/lovell/sharp/issues/4045
+  inputTiffGeo: getPath('bonne.geo.tif'), // https://download.osgeo.org/geotiff/samples/intergraph
 
   inputJp2: getPath('relax.jp2'), // https://www.fnordware.com/j2k/relax.jp2
   inputJp2TileParts: getPath('relax_tileparts.jp2'), // kdu_expand -i relax.jp2 -o relax-tmp.tif ; kdu_compress -i relax-tmp.tif -o relax_tileparts.jp2 -jp2_space sRGB Clayers=8 -rate 1.0,0.04 Stiles='{128,128}' ORGtparts=L ; rm relax-tmp.tif
diff --git a/test/unit/failOn.js b/test/unit/failOn.js
index 3e0dbabf..9add6778 100644
--- a/test/unit/failOn.js
+++ b/test/unit/failOn.js
@@ -103,4 +103,11 @@ describe('failOn', () => {
     fs.createReadStream(fixtures.inputJpgTruncated).pipe(writable);
     return writable.toBuffer();
   });
+
+  it('converts warnings to error for GeoTIFF', async () => {
+    await assert.rejects(
+      sharp(fixtures.inputTiffGeo).toBuffer(),
+      /Unknown field with tag 33550/
+    );
+  });
 });