diff --git a/Tests/test_file_ppm.py b/Tests/test_file_ppm.py
index 21a810e30..0ea6b277e 100644
--- a/Tests/test_file_ppm.py
+++ b/Tests/test_file_ppm.py
@@ -49,6 +49,13 @@ def test_pnm(tmp_path):
         with Image.open(f) as reloaded:
             assert_image_equal(im, reloaded)
 
+def test_not_ppm(tmp_path):
+    path = str(tmp_path / "temp.djvurle")
+    with open(path, "wb") as f:
+        f.write(b"PyXX")
+
+    with pytest.raises(UnidentifiedImageError):
+        Image.open(path)
 
 def test_header_with_comments(tmp_path):
     path = str(tmp_path / "temp.ppm")
@@ -67,6 +74,13 @@ def test_nondecimal_header(tmp_path):
     with pytest.raises(ValueError):
         Image.open(path)
 
+def test_token_too_long(tmp_path):
+    path = str(tmp_path / "temp.djvurle")
+    with open(path, "wb") as f:
+        f.write(b"P6\n 0123456789")
+
+    with pytest.raises(ValueError):
+        Image.open(path)
 
 def test_truncated_file(tmp_path):
     path = str(tmp_path / "temp.pgm")