diff --git a/src/PIL/TiffImagePlugin.py b/src/PIL/TiffImagePlugin.py
index 82ac47647fa..c78c223b365 100644
--- a/src/PIL/TiffImagePlugin.py
+++ b/src/PIL/TiffImagePlugin.py
@@ -245,6 +245,7 @@
     (MM, 3, (1,), 2, (4,), ()): ("P", "P;4R"),
     (II, 3, (1,), 1, (8,), ()): ("P", "P"),
     (MM, 3, (1,), 1, (8,), ()): ("P", "P"),
+    (II, 3, (1,), 1, (8, 8), (0,)): ("P", "PX"),
     (II, 3, (1,), 1, (8, 8), (2,)): ("PA", "PA"),
     (MM, 3, (1,), 1, (8, 8), (2,)): ("PA", "PA"),
     (II, 3, (1,), 2, (8,), ()): ("P", "P;R"),
diff --git a/src/libImaging/Unpack.c b/src/libImaging/Unpack.c
index a84dc0a6fd2..e351aa2f19b 100644
--- a/src/libImaging/Unpack.c
+++ b/src/libImaging/Unpack.c
@@ -1582,6 +1582,7 @@ static struct {
     {"P", "P", 8, copy1},
     {"P", "P;R", 8, unpackLR},
     {"P", "L", 8, copy1},
+    {"P", "PX", 16, unpackL16B},
 
     /* palette w. alpha */
     {"PA", "PA", 16, unpackLA},