diff --git a/Tests/test_file_ico.py b/Tests/test_file_ico.py
index b0d33e33f..f6244e086 100644
--- a/Tests/test_file_ico.py
+++ b/Tests/test_file_ico.py
@@ -14,6 +14,7 @@ class TestFileIco(PillowTestCase):
         self.assertEqual(im.mode, "RGBA")
         self.assertEqual(im.size, (16, 16))
         self.assertEqual(im.format, "ICO")
+        self.assertEqual(im.get_format_mimetype(), "image/x-icon")
 
     def test_invalid_file(self):
         with open("Tests/images/flower.jpg", "rb") as fp:
diff --git a/Tests/test_file_pcx.py b/Tests/test_file_pcx.py
index 9e42a86f7..7608db47c 100644
--- a/Tests/test_file_pcx.py
+++ b/Tests/test_file_pcx.py
@@ -13,6 +13,7 @@ class TestFilePcx(PillowTestCase):
         self.assertEqual(im2.mode, im.mode)
         self.assertEqual(im2.size, im.size)
         self.assertEqual(im2.format, "PCX")
+        self.assertEqual(im2.get_format_mimetype(), "image/x-pcx")
         self.assert_image_equal(im2, im)
 
     def test_sanity(self):
diff --git a/Tests/test_file_tga.py b/Tests/test_file_tga.py
index 0dbfb309c..a8ab00d7f 100644
--- a/Tests/test_file_tga.py
+++ b/Tests/test_file_tga.py
@@ -37,6 +37,8 @@ class TestFileTga(PillowTestCase):
                         path_no_ext, origin, "rle" if rle else "raw")
 
                     original_im = Image.open(tga_path)
+                    self.assertEqual(original_im.format, "TGA")
+                    self.assertEqual(original_im.get_format_mimetype(), "image/x-tga")
                     if rle:
                         self.assertEqual(
                             original_im.info["compression"], "tga_rle")