diff --git a/dll/win32/windowscodecs/tiffformat.c b/dll/win32/windowscodecs/tiffformat.c
index e7141fc3e23..b3d32eec611 100644
--- a/dll/win32/windowscodecs/tiffformat.c
+++ b/dll/win32/windowscodecs/tiffformat.c
@@ -1148,48 +1148,44 @@ static HRESULT TiffFrameDecode_ReadTile(TiffFrameDecode *This, UINT tile_x, UINT
 
         HeapFree(GetProcessHeap(), 0, srcdata);
     }
-    /* 4bpp RGBA */
+    /* 4bps RGBA */
     else if (This->decode_info.source_bpp == 4 && This->decode_info.samples == 4 && This->decode_info.bpp == 32)
     {
-        BYTE *src, *dst;
-        DWORD count;
+        BYTE *srcdata, *src, *dst;
+        DWORD x, y, count, width_bytes = (This->decode_info.tile_width * 3 + 7) / 8;
 
-        /* 1 source byte expands to 2 BGRA samples */
-        count = (This->decode_info.tile_width * This->decode_info.tile_height + 1) / 2;
+        count = width_bytes * This->decode_info.tile_height;
 
-        src = This->cached_tile + count - 1;
-        dst = This->cached_tile + This->decode_info.tile_size;
+        srcdata = HeapAlloc(GetProcessHeap(), 0, count);
+        if (!srcdata) return E_OUTOFMEMORY;
+        memcpy(srcdata, This->cached_tile, count);
 
-        while (count--)
+        for (y = 0; y < This->decode_info.tile_height; y++)
         {
-            BYTE b = *src--;
+            src = srcdata + y * width_bytes;
+            dst = This->cached_tile + y * This->decode_info.tile_width * 4;
 
-#ifdef __REACTOS__
-            dst -= 4;
-            dst[2] = (b & 0x08) ? 0xff : 0; /* R */
-            dst[1] = (b & 0x04) ? 0xff : 0; /* G */
-            dst[0] = (b & 0x02) ? 0xff : 0; /* B */
-            dst[3] = (b & 0x01) ? 0xff : 0; /* A */
-            if (count || This->decode_info.tile_width % 2 == 0)
+            /* 1 source byte expands to 2 BGRA samples */
+
+            for (x = 0; x < This->decode_info.tile_width; x += 2)
             {
-                dst -= 4;
-                dst[2] = (b & 0x80) ? 0xff : 0; /* R */
-                dst[1] = (b & 0x40) ? 0xff : 0; /* G */
-                dst[0] = (b & 0x20) ? 0xff : 0; /* B */
-                dst[3] = (b & 0x10) ? 0xff : 0; /* A */
+                dst[0] = (src[0] & 0x20) ? 0xff : 0; /* B */
+                dst[1] = (src[0] & 0x40) ? 0xff : 0; /* G */
+                dst[2] = (src[0] & 0x80) ? 0xff : 0; /* R */
+                dst[3] = (src[0] & 0x10) ? 0xff : 0; /* A */
+                if (x + 1 < This->decode_info.tile_width)
+                {
+                    dst[4] = (src[0] & 0x02) ? 0xff : 0; /* B */
+                    dst[5] = (src[0] & 0x04) ? 0xff : 0; /* G */
+                    dst[6] = (src[0] & 0x08) ? 0xff : 0; /* R */
+                    dst[7] = (src[0] & 0x01) ? 0xff : 0; /* A */
+                }
+                src++;
+                dst += 8;
             }
-#else
-            dst -= 8;
-            dst[2] = (b & 0x80) ? 0xff : 0; /* R */
-            dst[1] = (b & 0x40) ? 0xff : 0; /* G */
-            dst[0] = (b & 0x20) ? 0xff : 0; /* B */
-            dst[3] = (b & 0x10) ? 0xff : 0; /* A */
-            dst[6] = (b & 0x08) ? 0xff : 0; /* R */
-            dst[5] = (b & 0x04) ? 0xff : 0; /* G */
-            dst[4] = (b & 0x02) ? 0xff : 0; /* B */
-            dst[7] = (b & 0x01) ? 0xff : 0; /* A */
-#endif
         }
+
+        HeapFree(GetProcessHeap(), 0, srcdata);
     }
     /* 16bpp RGBA */
     else if (This->decode_info.source_bpp == 16 && This->decode_info.samples == 4 && This->decode_info.bpp == 32)
diff --git a/modules/rostests/winetests/windowscodecs/tiffformat.c b/modules/rostests/winetests/windowscodecs/tiffformat.c
index 8cdc0047a21..0c68904abad 100644
--- a/modules/rostests/winetests/windowscodecs/tiffformat.c
+++ b/modules/rostests/winetests/windowscodecs/tiffformat.c
@@ -302,6 +302,47 @@ static const struct tiff_24bpp_data
     { 900, 3 },
     { 0x11, 0x22, 0x33 }
 };
+
+static const struct tiff_4bps_bgra
+{
+    USHORT byte_order;
+    USHORT version;
+    ULONG  dir_offset;
+    USHORT number_of_entries;
+    struct IFD_entry entry[14];
+    ULONG next_IFD;
+    struct IFD_rational res;
+    BYTE pixel_data[4];
+} tiff_4bps_bgra =
+{
+#ifdef WORDS_BIGENDIAN
+    'M' | 'M' << 8,
+#else
+    'I' | 'I' << 8,
+#endif
+    42,
+    FIELD_OFFSET(struct tiff_4bps_bgra, number_of_entries),
+    14,
+    {
+        { 0xff, IFD_SHORT, 1, 0 }, /* SUBFILETYPE */
+        { 0x100, IFD_LONG, 1, 3 }, /* IMAGEWIDTH */
+        { 0x101, IFD_LONG, 1, 2 }, /* IMAGELENGTH */
+        { 0x102, IFD_SHORT, 1, 1 }, /* BITSPERSAMPLE */
+        { 0x103, IFD_SHORT, 1, 1 }, /* COMPRESSION */
+        { 0x106, IFD_SHORT, 1, 2 }, /* PHOTOMETRIC */
+        { 0x111, IFD_LONG, 1, FIELD_OFFSET(struct tiff_4bps_bgra, pixel_data) }, /* STRIPOFFSETS */
+        { 0x115, IFD_SHORT, 1, 4 }, /* SAMPLESPERPIXEL */
+        { 0x116, IFD_LONG, 1, 2 }, /* ROWSPERSTRIP */
+        { 0x117, IFD_LONG, 1, 4 }, /* STRIPBYTECOUNT */
+        { 0x11a, IFD_RATIONAL, 1, FIELD_OFFSET(struct tiff_4bps_bgra, res) }, /* XRESOLUTION */
+        { 0x11b, IFD_RATIONAL, 1, FIELD_OFFSET(struct tiff_4bps_bgra, res) }, /* YRESOLUTION */
+        { 0x11c, IFD_SHORT, 1, 1 }, /* PLANARCONFIGURATION */
+        { 0x128, IFD_SHORT, 1, 2 } /* RESOLUTIONUNIT */
+    },
+    0,
+    { 96, 1 },
+    { 0x12,0x30, 0x47,0xe0 }
+};
 #include "poppack.h"
 
 static IWICImagingFactory *factory;
@@ -1179,6 +1220,68 @@ static void test_color_formats(void)
     }
 }
 
+static void test_tiff_4bps_bgra(void)
+{
+    HRESULT hr;
+    IWICBitmapDecoder *decoder;
+    IWICBitmapFrameDecode *frame;
+    UINT frame_count, width, height, i;
+    double dpi_x, dpi_y;
+    IWICPalette *palette;
+    GUID format;
+    WICRect rc;
+    BYTE data[24];
+    static const BYTE expected_data[24] = { 0,0,0,0xff, 0xff,0,0,0, 0xff,0,0,0xff,
+                                            0,0xff,0,0, 0xff,0xff,0,0xff, 0xff,0xff,0xff,0 };
+
+    hr = create_decoder(&tiff_4bps_bgra, sizeof(tiff_4bps_bgra), &decoder);
+    ok(hr == S_OK, "Failed to load TIFF image data %#x\n", hr);
+    if (hr != S_OK) return;
+
+    hr = IWICBitmapDecoder_GetFrameCount(decoder, &frame_count);
+    ok(hr == S_OK, "GetFrameCount error %#x\n", hr);
+    ok(frame_count == 1, "expected 1, got %u\n", frame_count);
+
+    hr = IWICBitmapDecoder_GetFrame(decoder, 0, &frame);
+    ok(hr == S_OK, "GetFrame error %#x\n", hr);
+
+    hr = IWICBitmapFrameDecode_GetSize(frame, &width, &height);
+    ok(hr == S_OK, "GetSize error %#x\n", hr);
+    ok(width == 3, "got %u\n", width);
+    ok(height == 2, "got %u\n", height);
+
+    hr = IWICBitmapFrameDecode_GetResolution(frame, &dpi_x, &dpi_y);
+    ok(hr == S_OK, "GetResolution error %#x\n", hr);
+    ok(dpi_x == 96.0, "expected 96.0, got %f\n", dpi_x);
+    ok(dpi_y == 96.0, "expected 96.0, got %f\n", dpi_y);
+
+    hr = IWICBitmapFrameDecode_GetPixelFormat(frame, &format);
+    ok(hr == S_OK, "GetPixelFormat error %#x\n", hr);
+    ok(IsEqualGUID(&format, &GUID_WICPixelFormat32bppBGRA),
+       "got wrong format %s\n", wine_dbgstr_guid(&format));
+
+    hr = IWICImagingFactory_CreatePalette(factory, &palette);
+    ok(hr == S_OK, "CreatePalette error %#x\n", hr);
+    hr = IWICBitmapFrameDecode_CopyPalette(frame, palette);
+    ok(hr == WINCODEC_ERR_PALETTEUNAVAILABLE,
+       "expected WINCODEC_ERR_PALETTEUNAVAILABLE, got %#x\n", hr);
+    IWICPalette_Release(palette);
+
+    memset(data, 0xaa, sizeof(data));
+    rc.X = 0;
+    rc.Y = 0;
+    rc.Width = 3;
+    rc.Height = 2;
+    hr = IWICBitmapFrameDecode_CopyPixels(frame, &rc, 12, sizeof(data), data);
+    ok(hr == S_OK, "CopyPixels error %#x\n", hr);
+
+    for (i = 0; i < sizeof(data); i++)
+        ok(data[i] == expected_data[i], "%u: expected %02x, got %02x\n", i, expected_data[i], data[i]);
+
+    IWICBitmapFrameDecode_Release(frame);
+    IWICBitmapDecoder_Release(decoder);
+}
+
 START_TEST(tiffformat)
 {
     HRESULT hr;
@@ -1190,6 +1293,7 @@ START_TEST(tiffformat)
     ok(hr == S_OK, "CoCreateInstance error %#x\n", hr);
     if (FAILED(hr)) return;
 
+    test_tiff_4bps_bgra();
     test_color_formats();
     test_tiff_1bpp_palette();
     test_tiff_8bpp_palette();