diff --git a/adafruit_imageload/bmp/indexed.py b/adafruit_imageload/bmp/indexed.py
index e4ffd97..b1943f6 100644
--- a/adafruit_imageload/bmp/indexed.py
+++ b/adafruit_imageload/bmp/indexed.py
@@ -62,6 +62,8 @@ def load(file, width, height, data_start, colors, color_depth, *, bitmap=None, p
         bitmap = bitmap(width, height, colors)
         file.seek(data_start)
         line_size = width // (8 // color_depth)
+        if width % (8 // color_depth) != 0:
+            line_size += 1
         if line_size % 4 != 0:
             line_size += (4 - line_size % 4)
 
diff --git a/examples/images/1bit-not-byte-aligned.bmp b/examples/images/1bit-not-byte-aligned.bmp
new file mode 100644
index 0000000..0cad8c7
Binary files /dev/null and b/examples/images/1bit-not-byte-aligned.bmp differ