diff --git a/doc/installation.md b/doc/installation.md
index aa6968e26..d9483faef 100644
--- a/doc/installation.md
+++ b/doc/installation.md
@@ -81,7 +81,7 @@ usermod -a -G icingaweb2 apache
 
 SLES and OpenSUSE:
 ````
-usermod -G icingaweb2 wwwrun
+usermod -A icingaweb2 wwwrun
 ````
 
 Debian and Ubuntu:
diff --git a/icingaweb2.spec b/icingaweb2.spec
index 9a40e59e6..1d97819d9 100644
--- a/icingaweb2.spec
+++ b/icingaweb2.spec
@@ -202,7 +202,7 @@ cp -prv packages/files/config/modules/setup %{buildroot}/%{configdir}/modules/
 %pre
 getent group icingacmd >/dev/null || groupadd -r icingacmd
 %if 0%{?suse_version}
-usermod -G icingacmd,%{icingawebgroup} %{wwwuser}
+usermod -A icingacmd,%{icingawebgroup} %{wwwuser}
 %else
 usermod -a -G icingacmd,%{icingawebgroup} %{wwwuser}
 %endif