diff --git a/api4/file_test.go b/api4/file_test.go
index 70e32820c5..d955dca1ef 100644
--- a/api4/file_test.go
+++ b/api4/file_test.go
@@ -5,6 +5,7 @@ package api4
 
 import (
 	"bytes"
+	"encoding/hex"
 	"fmt"
 	"io"
 	"io/ioutil"
@@ -221,13 +222,13 @@ func TestUploadFiles(t *testing.T) {
 		// Upload a bunch of files, mixed images and non-images
 		{
 			title:             "Happy",
-			names:             []string{"test.png", "testgif.gif", "testplugin.tar.gz", "test-search.md", "test.tiff"},
+			names:             []string{"test.png", "testgif.gif", "testplugin.tar.gz", "test-search.md", "test_compressed_tiff.tiff"},
 			expectedCreatorId: th.BasicUser.Id,
 		},
 		// Upload a bunch of files, with clientIds
 		{
 			title:             "Happy client_ids",
-			names:             []string{"test.png", "testgif.gif", "testplugin.tar.gz", "test-search.md", "test.tiff"},
+			names:             []string{"test.png", "testgif.gif", "testplugin.tar.gz", "test-search.md", "test_compressed_tiff.tiff"},
 			clientIds:         []string{"1", "2", "3", "4", "5"},
 			expectedCreatorId: th.BasicUser.Id,
 		},
@@ -356,9 +357,20 @@ func TestUploadFiles(t *testing.T) {
 		// TIFF preview test
 		{
 			title:                       "Happy image thumbnail/preview 9",
-			names:                       []string{"test.tiff"},
-			expectedImageThumbnailNames: []string{"test_expected_thumb.tiff"},
-			expectedImagePreviewNames:   []string{"test_expected_preview.tiff"},
+			names:                       []string{"test_compressed_tiff.tiff"},
+			expectedImageThumbnailNames: []string{"test_expected_tiff_thumb.jpeg"},
+			expectedImagePreviewNames:   []string{"test_expected_tiff_preview.jpeg"},
+			expectImage:                 true,
+			expectedImageWidths:         []int{701},
+			expectedImageHeights:        []int{701},
+			expectedImageHasPreview:     []bool{true},
+			expectedCreatorId:           th.BasicUser.Id,
+		},
+		{
+			title:                       "Happy image thumbnail/preview 10",
+			names:                       []string{"test_raw_tiff.tiff"},
+			expectedImageThumbnailNames: []string{"test_expected_tiff_thumb.jpeg"},
+			expectedImagePreviewNames:   []string{"test_expected_tiff_preview.jpeg"},
 			expectImage:                 true,
 			expectedImageWidths:         []int{701},
 			expectedImageHeights:        []int{701},
@@ -609,10 +621,16 @@ func TestUploadFiles(t *testing.T) {
 							require.Nil(t, err)
 							if !bytes.Equal(data, expected) {
 								tf, err := ioutil.TempFile("", fmt.Sprintf("test_%v_*_%s", i, name))
+								defer tf.Close()
 								require.Nil(t, err)
-								_, _ = io.Copy(tf, bytes.NewReader(data))
-								tf.Close()
-								t.Errorf("Actual data mismatched %s, written to %q", name, tf.Name())
+								_, err = io.Copy(tf, bytes.NewReader(data))
+								require.Nil(t, err)
+								if strings.Contains(name, "test_expected_tiff") {
+									// TODO: remove this once MM-22056 is fixed.
+									t.Errorf("Actual data mismatched %s, written to %q - expected %d bytes, got %d. Previewer Image: \n\n%s\n", name, tf.Name(), len(expected), len(data), hex.Dump(data))
+								} else {
+									t.Errorf("Actual data mismatched %s, written to %q - expected %d bytes, got %d.", name, tf.Name(), len(expected), len(data))
+								}
 							}
 						}
 						if len(tc.expectedPayloadNames) == 0 {
diff --git a/app/post_metadata_test.go b/app/post_metadata_test.go
index f65ab845ff..24bda46ac9 100644
--- a/app/post_metadata_test.go
+++ b/app/post_metadata_test.go
@@ -2181,7 +2181,7 @@ func TestParseImages(t *testing.T) {
 			},
 		},
 		"tiff": {
-			FileName: "test.tiff",
+			FileName: "test_compressed_tiff.tiff",
 			Expected: (*model.PostImage)(nil),
 		},
 		"not an image": {
diff --git a/tests/test.tiff b/tests/test_compressed_tiff.tiff
similarity index 100%
rename from tests/test.tiff
rename to tests/test_compressed_tiff.tiff
diff --git a/tests/test_expected_preview.tiff b/tests/test_expected_tiff_preview.jpeg
similarity index 100%
rename from tests/test_expected_preview.tiff
rename to tests/test_expected_tiff_preview.jpeg
diff --git a/tests/test_expected_thumb.tiff b/tests/test_expected_tiff_thumb.jpeg
similarity index 100%
rename from tests/test_expected_thumb.tiff
rename to tests/test_expected_tiff_thumb.jpeg
diff --git a/tests/test_raw_tiff.tiff b/tests/test_raw_tiff.tiff
new file mode 100644
index 0000000000..5d5ec68f67
Binary files /dev/null and b/tests/test_raw_tiff.tiff differ