diff --git a/Tests/images/bmp/q/rgba32h56.bmp b/Tests/images/bmp/q/rgba32h56.bmp
new file mode 100644
index 000000000..343baa330
Binary files /dev/null and b/Tests/images/bmp/q/rgba32h56.bmp differ
diff --git a/Tests/test_bmp_reference.py b/Tests/test_bmp_reference.py
index 5398664b8..a5a4283e3 100644
--- a/Tests/test_bmp_reference.py
+++ b/Tests/test_bmp_reference.py
@@ -45,6 +45,7 @@ def test_questionable() -> None:
         "pal8rletrns.bmp",
         "rgb32bf-xbgr.bmp",
         "rgb32h52.bmp",
+        "rgba32h56.bmp",
     ]
     for f in get_files("q"):
         try:
diff --git a/src/PIL/BmpImagePlugin.py b/src/PIL/BmpImagePlugin.py
index dd8c06f4d..82a9c47db 100644
--- a/src/PIL/BmpImagePlugin.py
+++ b/src/PIL/BmpImagePlugin.py
@@ -53,7 +53,7 @@ def _accept(prefix: bytes) -> bool:
 
 
 def _dib_accept(prefix):
-    return i32(prefix) in [12, 40, 52, 64, 108, 124]
+    return i32(prefix) in [12, 40, 52, 56, 64, 108, 124]
 
 
 # =============================================================================
@@ -95,7 +95,7 @@ class BmpImageFile(ImageFile.ImageFile):
 
         # --------------------------------------------- Windows Bitmap v2 to v5
         # v3, OS/2 v2, v4, v5
-        elif file_info["header_size"] in (40, 52, 64, 108, 124):
+        elif file_info["header_size"] in (40, 52, 56, 64, 108, 124):
             file_info["y_flip"] = header_data[7] == 0xFF
             file_info["direction"] = 1 if file_info["y_flip"] else -1
             file_info["width"] = i32(header_data, 0)