diff --git a/.travis.yml b/.travis.yml
index 0315248..0eb10a6 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -3,12 +3,12 @@ compiler:
   - gcc
   - clang
 env:
-  - CONFIGURE_ARGS=""
-  - CONFIGURE_ARGS="--without-ldap"
-  - CONFIGURE_ARGS="--without-cr"
+  - CONFIGURE_ARGS="" EXTRA="libldap2-dev libykpers-1-dev libnet-ldap-server-perl"
+  - CONFIGURE_ARGS="--without-ldap" EXTRA="libykpers-1-dev"
+  - CONFIGURE_ARGS="--without-cr" EXTRA="libldap2-dev libnet-ldap-server-perl"
   - CONFIGURE_ARGS="--without-ldap --without-cr"
 before_install:
   - sudo add-apt-repository -y ppa:yubico/stable
   - sudo apt-get update -qq
-  - sudo apt-get install -qq -y --no-install-recommends libykclient-dev libpam0g-dev libldap2-dev libykpers-1-dev libyubikey-dev asciidoc docbook-xml xsltproc libxml2-utils
+  - sudo apt-get install -qq -y --no-install-recommends libykclient-dev libpam0g-dev libyubikey-dev asciidoc docbook-xml xsltproc libxml2-utils $EXTRA
 script: autoreconf -i && ./configure $CONFIGURE_ARGS && make check