diff --git a/Tests/test_file_png.py b/Tests/test_file_png.py
index c4db9790524..7302713cbe6 100644
--- a/Tests/test_file_png.py
+++ b/Tests/test_file_png.py
@@ -92,11 +92,11 @@ def test_sanity(self, tmp_path):
             assert im.format == "PNG"
             assert im.get_format_mimetype() == "image/png"
 
-        for mode in ["1", "L", "P", "RGB", "I", "I;16"]:
+        for mode in ["1", "L", "P", "RGB", "I", "I;16", "I;16B"]:
             im = hopper(mode)
             im.save(test_file)
             with Image.open(test_file) as reloaded:
-                if mode == "I;16":
+                if mode in ("I;16", "I;16B"):
                     reloaded = reloaded.convert(mode)
                 assert_image_equal(reloaded, im)
 
diff --git a/src/PIL/PngImagePlugin.py b/src/PIL/PngImagePlugin.py
index bfa8cb7ac66..35d1a4d7d0e 100644
--- a/src/PIL/PngImagePlugin.py
+++ b/src/PIL/PngImagePlugin.py
@@ -1042,6 +1042,7 @@ def getxmp(self):
     "LA": ("LA", b"\x08\x04"),
     "I": ("I;16B", b"\x10\x00"),
     "I;16": ("I;16B", b"\x10\x00"),
+    "I;16B": ("I;16B", b"\x10\x00"),
     "P;1": ("P;1", b"\x01\x03"),
     "P;2": ("P;2", b"\x02\x03"),
     "P;4": ("P;4", b"\x04\x03"),