diff --git a/Tests/test_imagecms.py b/Tests/test_imagecms.py
index 66be02078ad..cd539d990ed 100644
--- a/Tests/test_imagecms.py
+++ b/Tests/test_imagecms.py
@@ -626,6 +626,9 @@ def test_constants_deprecation():
             with pytest.warns(DeprecationWarning):
                 assert getattr(ImageCms, prefix + name) == enum[name]
 
+def test_long_modes() -> None:
+    p = ImageCms.getOpenProfile("Tests/icc/sGrey-v2-nano.icc")
+    ImageCms.buildTransform(p, p, "ABCDEFGHI", "ABCDEFGHI")
 
 @pytest.mark.parametrize("mode", ("RGB", "RGBA", "RGBX"))
 def test_rgb_lab(mode):
diff --git a/src/_imagingcms.c b/src/_imagingcms.c
index ddfe6ad6486..a10c336feb8 100644
--- a/src/_imagingcms.c
+++ b/src/_imagingcms.c
@@ -201,8 +201,8 @@ cms_transform_new(cmsHTRANSFORM transform, char *mode_in, char *mode_out) {
 
     self->transform = transform;
 
-    strcpy(self->mode_in, mode_in);
-    strcpy(self->mode_out, mode_out);
+    strncpy(self->mode_in, mode_in, 8);
+    strncpy(self->mode_out, mode_out, 8);
 
     return (PyObject *)self;
 }