diff --git a/wscript b/wscript
index 6a5db1ab..2b1b66c8 100644
--- a/wscript
+++ b/wscript
@@ -33,10 +33,10 @@ def configure (conf):
         nls = 'no'
     conf.check_message_custom ('localization', 'support', nls)
 
-    conf.check_pkg ('gtk+-2.0', destvar='GTK', vnum='2.6.0')
-    conf.check_pkg ('webkit-1.0', destvar='WEBKIT', vnum='0.1')
-    conf.check_pkg ('libxml-2.0', destvar='LIBXML', vnum='2.6')
-    conf.check_pkg ('libsexy', destvar='LIBSEXY', vnum='0.1')
+    conf.check_pkg ('gtk+-2.0', destvar='GTK', vnum='2.6.0', mandatory=True)
+    conf.check_pkg ('webkit-1.0', destvar='WEBKIT', vnum='0.1', mandatory=True)
+    conf.check_pkg ('libxml-2.0', destvar='LIBXML', vnum='2.6', mandatory=True)
+    conf.check_pkg ('libsexy', destvar='LIBSEXY', vnum='0.1', mandatory=True)
 
     if conf.find_program ('convert', var='CONVERT'):
         icons = 'yes'