diff --git a/lib/chkconfig.ltx b/lib/chkconfig.ltx
index e655e6c56b..b5e5044b7e 100644
--- a/lib/chkconfig.ltx
+++ b/lib/chkconfig.ltx
@@ -330,6 +330,8 @@
 \TestPackage{lmodern}
 \TestPackage{luximono}
 \TestPackage{tipa}
+% necessary to get correct size for InstantPreview images created by dvipng
+\TestPackage[c70fs.fd]{zhmetrics}
 
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%