diff --git a/guacamole-docker/README.md b/guacamole-docker/README.md
index e800345eb..78631e852 100644
--- a/guacamole-docker/README.md
+++ b/guacamole-docker/README.md
@@ -91,7 +91,7 @@ To generate a SQL script which can be used to initialize a fresh PostgreSQL
 database
 [as documented in the Guacamole manual](http://guacamole.apache.org/doc/gug/jdbc-auth.html#jdbc-auth-postgresql):
 
-    docker run --rm guacamole/guacamole /opt/guacamole/bin/initdb.sh --postgres > initdb.sql
+    docker run --rm guacamole/guacamole /opt/guacamole/bin/initdb.sh --postgresql > initdb.sql
 
 Alternatively, you can use the SQL scripts included with the
 guacamole-auth-jdbc extension from
diff --git a/guacamole-docker/bin/initdb.sh b/guacamole-docker/bin/initdb.sh
index 6031189c9..aa92b66bb 100755
--- a/guacamole-docker/bin/initdb.sh
+++ b/guacamole-docker/bin/initdb.sh
@@ -26,7 +26,7 @@
 ##
 ## @param DATABASE
 ##     The database to generate the SQL script for. This may be either
-##     "--postgres", for PostgreSQL, "--mysql" for MySQL, or "--sqlserver" for Microsoft SQL Server.
+##     "--postgresql", for PostgreSQL, "--mysql" for MySQL, or "--sqlserver" for Microsoft SQL Server.
 ##
 
 DATABASE="$1"
@@ -37,7 +37,7 @@ DATABASE="$1"
 ##
 incorrect_usage() {
     cat <<END
-USAGE: /opt/guacamole/bin/initdb.sh [--postgres | --mysql | --sqlserver]
+USAGE: /opt/guacamole/bin/initdb.sh [--postgresql | --mysql | --sqlserver]
 END
     exit 1
 }
@@ -54,7 +54,7 @@ fi
 
 case $DATABASE in
 
-    --postgres)
+    --postgresql)
         cat /opt/guacamole/postgresql/schema/*.sql
         ;;