diff --git a/dlls/windowscodecs/pngformat.c b/dlls/windowscodecs/pngformat.c
index d0977b4d1dd..686f9c6391a 100644
--- a/dlls/windowscodecs/pngformat.c
+++ b/dlls/windowscodecs/pngformat.c
@@ -625,7 +625,7 @@ static HRESULT WINAPI PngDecoder_GetColorContexts(IWICBitmapDecoder *iface,
     UINT cCount, IWICColorContext **ppIColorContexts, UINT *pcActualCount)
 {
     FIXME("(%p,%u,%p,%p)\n", iface, cCount, ppIColorContexts, pcActualCount);
-    return E_NOTIMPL;
+    return WINCODEC_ERR_UNSUPPORTEDOPERATION;
 }
 
 static HRESULT WINAPI PngDecoder_GetThumbnail(IWICBitmapDecoder *iface,
@@ -845,7 +845,7 @@ static HRESULT WINAPI PngDecoder_Frame_GetColorContexts(IWICBitmapFrameDecode *i
     UINT cCount, IWICColorContext **ppIColorContexts, UINT *pcActualCount)
 {
     FIXME("(%p,%u,%p,%p): stub\n", iface, cCount, ppIColorContexts, pcActualCount);
-    return E_NOTIMPL;
+    return WINCODEC_ERR_UNSUPPORTEDOPERATION;
 }
 
 static HRESULT WINAPI PngDecoder_Frame_GetThumbnail(IWICBitmapFrameDecode *iface,
diff --git a/dlls/windowscodecs/tiffformat.c b/dlls/windowscodecs/tiffformat.c
index 05b6aba81cd..cf93540cecc 100644
--- a/dlls/windowscodecs/tiffformat.c
+++ b/dlls/windowscodecs/tiffformat.c
@@ -649,7 +649,7 @@ static HRESULT WINAPI TiffDecoder_GetColorContexts(IWICBitmapDecoder *iface,
     UINT cCount, IWICColorContext **ppIColorContexts, UINT *pcActualCount)
 {
     FIXME("(%p,%u,%p,%p)\n", iface, cCount, ppIColorContexts, pcActualCount);
-    return E_NOTIMPL;
+    return WINCODEC_ERR_UNSUPPORTEDOPERATION;
 }
 
 static HRESULT WINAPI TiffDecoder_GetThumbnail(IWICBitmapDecoder *iface,
@@ -1099,7 +1099,7 @@ static HRESULT WINAPI TiffFrameDecode_GetColorContexts(IWICBitmapFrameDecode *if
     UINT cCount, IWICColorContext **ppIColorContexts, UINT *pcActualCount)
 {
     FIXME("(%p,%u,%p,%p): stub\n", iface, cCount, ppIColorContexts, pcActualCount);
-    return E_NOTIMPL;
+    return WINCODEC_ERR_UNSUPPORTEDOPERATION;
 }
 
 static HRESULT WINAPI TiffFrameDecode_GetThumbnail(IWICBitmapFrameDecode *iface,