diff --git a/Tests/test_lib_pack.py b/Tests/test_lib_pack.py
index f7812f62bd8..963d35b067e 100644
--- a/Tests/test_lib_pack.py
+++ b/Tests/test_lib_pack.py
@@ -340,6 +340,10 @@ def test_RGB(self):
             self.assert_unpack("RGB", "G;16N", 2, (0, 1, 0), (0, 3, 0), (0, 5, 0))
             self.assert_unpack("RGB", "B;16N", 2, (0, 0, 1), (0, 0, 3), (0, 0, 5))
 
+        self.assert_unpack(
+            "RGB", "CMYK", 4, (250, 249, 248), (242, 241, 240), (234, 233, 233)
+        )
+
     def test_RGBA(self):
         self.assert_unpack("RGBA", "LA", 2, (1, 1, 1, 2), (3, 3, 3, 4), (5, 5, 5, 6))
         self.assert_unpack(
diff --git a/src/libImaging/Unpack.c b/src/libImaging/Unpack.c
index 206403ba6e0..6e86e723297 100644
--- a/src/libImaging/Unpack.c
+++ b/src/libImaging/Unpack.c
@@ -813,6 +813,20 @@ ImagingUnpackXBGR(UINT8 *_out, const UINT8 *in, int pixels) {
     }
 }
 
+static void
+cmyk2rgb(UINT8 *_out, const UINT8 *in, int pixels) {
+    int i, nk, tmp;
+    for (i = 0; i < pixels; i++) {
+        nk = 255 - in[3];
+        _out[0] = CLIP8(nk - MULDIV255(in[0], nk, tmp));
+        _out[1] = CLIP8(nk - MULDIV255(in[1], nk, tmp));
+        _out[2] = CLIP8(nk - MULDIV255(in[2], nk, tmp));
+        _out[3] = 255;
+        _out += 4;
+        in += 4;
+    }
+}
+
 /* Unpack to "RGBA" image */
 
 static void
@@ -1589,6 +1603,7 @@ static struct {
     {"RGB", "R;16B", 16, band016B},
     {"RGB", "G;16B", 16, band116B},
     {"RGB", "B;16B", 16, band216B},
+    {"RGB", "CMYK", 32, cmyk2rgb},
 
     /* true colour w. alpha */
     {"RGBA", "LA", 16, unpackRGBALA},