diff --git a/startkde/startkde.cmake b/startkde/startkde.cmake
index f9e2e42..2ced21c 100644
--- a/startkde/startkde.cmake
+++ b/startkde/startkde.cmake
@@ -224,15 +224,6 @@ fi
 
 echo 'startkde: Starting up...'  1>&2
 
-# Make sure that the KDE prefix is first in XDG_DATA_DIRS and that it's set at all.
-# The spec allows XDG_DATA_DIRS to be not set, but X session startup scripts tend
-# to set it to a list of paths *not* including the KDE prefix if it's not /usr or
-# /usr/local.
-if test -z "$XDG_DATA_DIRS"; then
-    XDG_DATA_DIRS="@KDE_INSTALL_FULL_DATAROOTDIR@:/usr/share:/usr/local/share"
-fi
-export XDG_DATA_DIRS
-
 # Mark that full KDE session is running (e.g. Konqueror preloading works only
 # with full KDE running). The KDE_FULL_SESSION property can be detected by
 # any X client connected to the same X session, even if not launched
diff --git a/startkde/startplasmacompositor.cmake b/startkde/startplasmacompositor.cmake
index dd9e304..de3f0ed 100644
--- a/startkde/startplasmacompositor.cmake
+++ b/startkde/startplasmacompositor.cmake
@@ -165,15 +165,6 @@ done
 
 echo 'startplasmacompositor: Starting up...'  1>&2
 
-# Make sure that the KDE prefix is first in XDG_DATA_DIRS and that it's set at all.
-# The spec allows XDG_DATA_DIRS to be not set, but X session startup scripts tend
-# to set it to a list of paths *not* including the KDE prefix if it's not /usr or
-# /usr/local.
-if test -z "$XDG_DATA_DIRS"; then
-XDG_DATA_DIRS="@KDE_INSTALL_FULL_DATADIR@:/usr/share:/usr/local/share"
-fi
-export XDG_DATA_DIRS
-
 # Make sure that D-Bus is running
 if qdbus >/dev/null 2>/dev/null; then
     : # ok