diff --git a/libImaging/Jpeg2KDecode.c b/libImaging/Jpeg2KDecode.c
index 9c4e16b1f..a39c700ed 100644
--- a/libImaging/Jpeg2KDecode.c
+++ b/libImaging/Jpeg2KDecode.c
@@ -410,6 +410,60 @@ j2ku_srgba_rgba(opj_image_t *in, const JPEG2KTILEINFO *tileinfo,
     }
 }
 
+static void
+j2ku_sycca_rgba(opj_image_t *in, const JPEG2KTILEINFO *tileinfo,
+                const UINT8 *tiledata, Imaging im)
+{
+    unsigned x0 = tileinfo->x0, y0 = tileinfo->y0;
+    unsigned w = tileinfo->x1 - tileinfo->x0;
+    unsigned h = tileinfo->y1 - tileinfo->y0;
+
+    int shifts[4], offsets[4], csiz[4];
+    const UINT8 *cdata[4];
+    const UINT8 *cptr = tiledata;
+    unsigned n, x, y;
+
+    for (n = 0; n < 4; ++n) {
+        cdata[n] = cptr;
+        shifts[n] = 8 - in->comps[n].prec;
+        offsets[n] = in->comps[n].sgnd ? 1 << (in->comps[n].prec - 1) : 0;
+        csiz[n] = (in->comps[n].prec + 7) >> 3;
+
+        if (csiz[n] == 3)
+            csiz[n] = 4;
+
+        if (shifts[n] < 0)
+            offsets[n] += 1 << (-shifts[n] - 1);
+
+        cptr += csiz[n] * w * h;
+    }
+
+    for (y = 0; y < h; ++y) {
+        const UINT8 *data[4];
+        UINT8 *row = (UINT8 *)im->image[y0 + y] + x0 * 4;
+        UINT8 *row_start = row;
+        for (n = 0; n < 4; ++n)
+            data[n] = &cdata[n][csiz[n] * y * w];
+        
+        for (x = 0; x < w; ++x) {
+            for (n = 0; n < 4; ++n) {
+                UINT32 word;
+
+                switch (csiz[n]) {
+                case 1: word = *data[n]++; break;
+                case 2: word = *(const UINT16 *)data[n]; data[n] += 2; break;
+                case 4: word = *(const UINT32 *)data[n]; data[n] += 4; break;
+                }
+
+                row[n] = j2ku_shift(offsets[n] + word, shifts[n]);
+            }
+            row += 4;
+        }
+
+        ImagingConvertYCbCr2RGB(row_start, row_start, w);
+    }
+}
+
 static const struct j2k_decode_unpacker j2k_unpackers[] = {
     { "L", OPJ_CLRSPC_GRAY, 1, j2ku_gray_l },
     { "LA", OPJ_CLRSPC_GRAY, 2, j2ku_graya_la },
@@ -417,11 +471,14 @@ static const struct j2k_decode_unpacker j2k_unpackers[] = {
     { "RGB", OPJ_CLRSPC_GRAY, 2, j2ku_gray_rgb },
     { "RGB", OPJ_CLRSPC_SRGB, 3, j2ku_srgb_rgb },
     { "RGB", OPJ_CLRSPC_SYCC, 3, j2ku_sycc_rgb },
+    { "RGB", OPJ_CLRSPC_SRGB, 4, j2ku_srgb_rgb },
+    { "RGB", OPJ_CLRSPC_SYCC, 4, j2ku_sycc_rgb },
     { "RGBA", OPJ_CLRSPC_GRAY, 1, j2ku_gray_rgb },
     { "RGBA", OPJ_CLRSPC_GRAY, 2, j2ku_graya_la },
     { "RGBA", OPJ_CLRSPC_SRGB, 3, j2ku_srgb_rgb },
     { "RGBA", OPJ_CLRSPC_SYCC, 3, j2ku_sycc_rgb },
     { "RGBA", OPJ_CLRSPC_SRGB, 4, j2ku_srgba_rgba },
+    { "RGBA", OPJ_CLRSPC_SYCC, 4, j2ku_sycca_rgba },
 };
 
 /* -------------------------------------------------------------------- */