diff --git a/guacamole-docker/bin/start.sh b/guacamole-docker/bin/start.sh
index ab0fdc865..33dc35a14 100755
--- a/guacamole-docker/bin/start.sh
+++ b/guacamole-docker/bin/start.sh
@@ -374,7 +374,7 @@ make sure they are readable for the user in the container.
 END
         exit 1;
     fi
-    if [ "$RADIUS_AUTH_PROTOCOL" == "eap-ttls" -a -z "$RADIUS_EAP_TTLS_INNER_PROTOCOL" ]; then
+    if [ "$RADIUS_AUTH_PROTOCOL" = "eap-ttls" -a -z "$RADIUS_EAP_TTLS_INNER_PROTOCOL" ]; then
        cat <<END
 FATAL: Authentication protocol "eap-ttls" specified but
        RADIUS_EAP_TTLS_INNER_PROTOCOL is not set!