diff --git a/Makefile b/Makefile
index 9810a73f6..51da76817 100644
--- a/Makefile
+++ b/Makefile
@@ -124,10 +124,11 @@ build/news-atom.xml build/news-archiv-atom.xml : PFLAGS+=--stringparam prefix ""
 build/news-atom.xml build/news-archiv-atom.xml : VFLAGS_OUT=$(VFLAGS) --relaxng xsd/atom.rng
 build/podcast.xml build/podcast-archiv.xml : STYLE=xsl/podcast.xsl
 build/podcast.xml build/podcast-archiv.xml : VFLAGS_OUT=$(VFLAGS) --schema xsd/rss20.xsd
+build/podcast.xml build/podcast-archiv.xml : PFLAGS+=--stringparam format audio/mpeg
 build/podcast.xml build/podcast-archiv.xml: xsl/podcast.xsl # Does not work with $(STYLE) - why?
 build/pentaradio.xml build/pentaradio-archiv.xml : STYLE=xsl/podcast.xsl
 build/pentaradio.xml build/pentaradio-archiv.xml : VFLAGS_OUT=$(VFLAGS) --schema xsd/rss20.xsd
-build/pentaradio.xml build/pentaradio-archiv.xml : PFLAGS+=--stringparam selection pentaradio
+build/pentaradio.xml build/pentaradio-archiv.xml : PFLAGS+=--stringparam selection pentaradio --stringparam format audio/mpeg
 build/pentaradio.xml build/pentaradio-archiv.xml: xsl/podcast.xsl # Does not work with $(STYLE) - why?
 build/pentacast.xml build/pentacast-archiv.xml : STYLE=xsl/podcast.xsl
 build/pentacast.xml build/pentacast-archiv.xml : VFLAGS_OUT=$(VFLAGS) --schema xsd/rss20.xsd
@@ -141,11 +142,11 @@ build/pentacast-ogg.xml build/pentacast-ogg-archiv.xml : xsl/podcast.xsl # Does
 
 build/pentamusic.xml build/pentamusic-archiv.xml : STYLE=xsl/podcast.xsl
 build/pentamusic.xml build/pentamusic-archiv.xml : VFLAGS_OUT=$(VFLAGS) --schema xsd/rss20.xsd
-build/pentamusic.xml build/pentamusic-archiv.xml : PFLAGS+=--stringparam selection pentamusic
+build/pentamusic.xml build/pentamusic-archiv.xml : PFLAGS+=--stringparam selection pentamusic --stringparam format audio/mpeg
 build/pentamusic.xml build/pentamusic-archiv.xml: xsl/podcast.xsl # Does not work with $(STYLE) - why?
 build/pentamedia.xml build/pentamedia-archiv.xml : STYLE=xsl/podcast.xsl
 build/pentamedia.xml build/pentamedia-archiv.xml : VFLAGS_OUT=$(VFLAGS) --schema xsd/rss20.xsd
-build/pentamedia.xml build/pentamedia-archiv.xml : PFLAGS+=--stringparam selection pentamedia
+build/pentamedia.xml build/pentamedia-archiv.xml : PFLAGS+=--stringparam selection pentamedia --stringparam format audio/mpeg
 build/pentamedia.xml build/pentamedia-archiv.xml: xsl/podcast.xsl # Does not work with $(STYLE) - why?
 
 #.INTERMEDIATE: news.xml