diff --git a/builder/dockerfile.opensuse_15.barebones.rpm.test b/builder/dockerfile.opensuse_15.barebones.rpm.test
index 89f1fbf..d30eabb 100644
--- a/builder/dockerfile.opensuse_15.barebones.rpm.test
+++ b/builder/dockerfile.opensuse_15.barebones.rpm.test
@@ -8,23 +8,8 @@ RUN zypper -n install -y \
   vim \
   xterm
 
-# deps and rpm install
-RUN zypper -n install -y \
-  libglvnd \
-  libgomp1 \
-  libjpeg8 \
-  libpixman-1-0 \
-  libXdmcp6 \
-  libXfont2-2 \
-  libxkbcommon-x11-0 \
-  openssl \
-  perl \
-  x11-tools \
-  xauth \
-  xkbcomp \
-  xkeyboard-config && \
-  mkdir -p /etc/pki/tls/private
-
+# Cache repo updates, so that package changes don't trigger it on every build.
+RUN zypper refresh
 ARG KASMVNC_PACKAGE_DIR
 COPY $KASMVNC_PACKAGE_DIR/*.rpm /tmp
 RUN zypper install -y --allow-unsigned-rpm /tmp/*.rpm
diff --git a/builder/dockerfile.opensuse_15.rpm.build b/builder/dockerfile.opensuse_15.rpm.build
index b074784..d646c8a 100644
--- a/builder/dockerfile.opensuse_15.rpm.build
+++ b/builder/dockerfile.opensuse_15.rpm.build
@@ -14,7 +14,10 @@ RUN zypper -n install -y \
   tree \
   vim
 
+# Cache repo updates, so that spec changes don't trigger it on every build.
+RUN zypper refresh
 COPY opensuse/*.spec /tmp
+
 RUN zypper -n install $(grep BuildRequires /tmp/*.spec | cut -d' ' -f2 | xargs)
 
 RUN useradd -u 1000 -m -d /home/docker docker && \
diff --git a/opensuse/kasmvncserver.spec b/opensuse/kasmvncserver.spec
index 901bd0a..618e812 100644
--- a/opensuse/kasmvncserver.spec
+++ b/opensuse/kasmvncserver.spec
@@ -46,6 +46,7 @@ SRC=$TAR_DATA/usr/local
 SRC_BIN=$SRC/bin
 DESTDIR=$RPM_BUILD_ROOT
 DST_MAN=$DESTDIR/usr/share/man/man1
+SSL_CERT_DIR=/usr/share/pki/trust/anchors
 
 mkdir -p $DESTDIR/usr/bin $DESTDIR/usr/share/man/man1 \
   $DESTDIR/usr/share/doc/kasmvncserver $DESTDIR/usr/lib \
@@ -63,9 +64,9 @@ rsync -r --exclude '.git*' --exclude po2js --exclude xgettext-html \
   --exclude www/utils/ --exclude .eslintrc --exclude configure \
   $SRC/share/kasmvnc $DESTDIR/usr/share
 
-sed -i -e 's!pem_certificate: .\+$!pem_certificate: /etc/pki/tls/private/kasmvnc.pem!' \
+sed -i -e 's!pem_certificate: .\+$!pem_certificate: '$SSL_CERT_DIR'/kasmvnc.pem!' \
     $DESTDIR/usr/share/kasmvnc/kasmvnc_defaults.yaml
-sed -i -e 's!pem_key: .\+$!pem_key: /etc/pki/tls/private/kasmvnc.pem!' \
+sed -i -e 's!pem_key: .\+$!pem_key: '$SSL_CERT_DIR'/kasmvnc.pem!' \
     $DESTDIR/usr/share/kasmvnc/kasmvnc_defaults.yaml
 sed -e 's/^\([^#]\)/# \1/' $DESTDIR/usr/share/kasmvnc/kasmvnc_defaults.yaml > \
   $DESTDIR/etc/kasmvnc/kasmvnc.yaml
@@ -104,7 +105,7 @@ cd $DST_MAN && ln -s vncpasswd.1 kasmvncpasswd.1;
   }
 
   make_self_signed_certificate() {
-    local cert_file=/etc/pki/tls/private/kasmvnc.pem
+    local cert_file="/usr/share/pki/trust/anchors/kasmvnc.pem"
     [ -f "$cert_file" ] && return 0
 
     openssl req -x509 -nodes -days 3650 -newkey rsa:2048 \
@@ -119,4 +120,4 @@ cd $DST_MAN && ln -s vncpasswd.1 kasmvncpasswd.1;
   make_self_signed_certificate
 
 %postun
-  rm -f /etc/pki/tls/private/kasmvnc.pem
+  rm -f /usr/share/pki/trust/anchors/kasmvnc.pem