diff --git a/webbuild/webbuild-cgi b/webbuild/webbuild-cgi
index 32e4177..4b67cde 100755
--- a/webbuild/webbuild-cgi
+++ b/webbuild/webbuild-cgi
@@ -1439,10 +1439,12 @@ if [ "$MAINTAINERMODE" != "true" ]; then
       # check for updates
       echo -n "<input type=button value=\"check for updates\" onclick="
       echo -n "ajax_getvalues(\"ENVIRONMENT=$ENVIRONMENT&REPOSITORY=$REPOSITORY&PACKAGE=$PACKAGEENCODED&REQUEST=autospecupdatescheck&"
+      echo -n "RPMBUILDARCH=\"+getSelectedValueById('rpmbuildarch')+\"&"
       echo -n "SPECTEXT=\"+encodeURIComponent(editor.getValue()));>"
       # unpack
       echo -n "<input type=button value=\"prepare\" onclick="
       echo -n "ajax_getvalues(\"ENVIRONMENT=$ENVIRONMENT&REPOSITORY=$REPOSITORY&PACKAGE=$PACKAGEENCODED&REQUEST=rpmprepare&"
+      echo -n "RPMBUILDARCH=\"+getSelectedValueById('rpmbuildarch')+\"&"
       echo -n "SPECTEXT=\"+encodeURIComponent(editor.getValue()));>"
       # build
       echo -n "<input type=button value=\"build\" onclick="
@@ -1751,7 +1753,11 @@ case $REQUEST in
                fi
                ;;
    "autospecupdatescheck") $SUDO_WRAPPER 0 $ENVIRONMENT "$USER" $PACKAGE "$AUTOSPEC_CMD -u $PACKAGE -a2"; RET=$? ;;
-   "rpmprepare") $SUDO_WRAPPER 0 $ENVIRONMENT "$USER" $PACKAGE "rpmbuild -bp $PACKAGE.spec --nodeps --define=\"_topdir $SPECVAR_WORKINGHOME/RPM\""; RET=$? ;;
+   "rpmprepare") [ "$RPMBUILDARCH" -a "$RPMBUILDARCH" != "${AUTOPORT_ARCH[$ENVIRONMENT]}" ] && \
+                    RPMARCHADD="--target $RPMBUILDARCH --define=\"cross_target_cpu $RPMBUILDARCH\""
+                 $SUDO_WRAPPER 0 $ENVIRONMENT "$USER" $PACKAGE "rpmbuild -bp $PACKAGE.spec $RPMARCHADD --nodeps --define=\"_topdir $SPECVAR_WORKINGHOME/RPM\""
+                 RET=$?
+                 ;;
    "rpmbuild") [ "$RPMFORCE" = "true" ] && RPMFORCEADD="--force-build"
                [ "$RPMBUILDARCH" -a "$RPMBUILDARCH" != "${AUTOPORT_ARCH[$ENVIRONMENT]}" ] && \
                   RPMARCHADD="-A $RPMBUILDARCH --define \"cross_target_cpu=$RPMBUILDARCH\""