diff --git a/spk/imagemagick/Makefile b/spk/imagemagick/Makefile
index 3ebb4e4060a..23b2a5dd6fc 100644
--- a/spk/imagemagick/Makefile
+++ b/spk/imagemagick/Makefile
@@ -3,14 +3,18 @@ SPK_VERS = 7.1.1
SPK_REV = 11
SPK_ICON = src/imagemagick.png
-DEPENDS = cross/imagemagick
+# WARNING: pngquant will fail when built after cross/zlib (i.e. cross/libpng)
+# with prebuilt ffmpeg this is not a problem
+# without prebuilt ffmpeg the "DEPENDS += cross/ffmpeg*" must be defined below
+DEPENDS = cross/pngquant
+DEPENDS += cross/imagemagick
# additional tools for image compression:
DEPENDS += cross/jpegoptim cross/pngcrush
MAINTAINER = SynoCommunity
DESCRIPTION = ImageMagick is a software suite to create, edit, compose, or convert bitmap images. This package includes some tools for image compression, that are not part of imagemagick: jpegoptim, a utility to optimize/compress JPEG files; pngcrush an optimizer for png files.
DISPLAY_NAME = ImageMagick
-CHANGELOG = "1. Update ImageMagick to v7.1.1-33 and jpegoptim to v1.5.5.
2. Update libraries to current versions (fontconfig, freetype, giflib, libpng, libtiff, libwebp, openjpeg)."
+CHANGELOG = "1. Update ImageMagick to v7.1.1-33 and jpegoptim to v1.5.5.
2. Update libraries to current versions (fontconfig, freetype, giflib, libpng, libtiff, libwebp, openjpeg)
3. Add pngquant."
STARTABLE = no
@@ -22,6 +26,7 @@ POST_STRIP_TARGET = imagemagick_extra_install
SPK_COMMANDS = bin/magick bin/magick-script bin/animate bin/compare bin/composite bin/conjure
SPK_COMMANDS += bin/convert bin/display bin/identify bin/import bin/mogrify bin/montage bin/stream
# additional tools:
+SPK_COMMANDS += bin/pngquant
SPK_COMMANDS += bin/jpegoptim
SPK_COMMANDS += bin/pngcrush