diff --git a/scripts/tests/realm-boot.sh b/scripts/tests/realm-boot.sh
index 14ec2c964c08e..310bb7869845c 100755
--- a/scripts/tests/realm-boot.sh
+++ b/scripts/tests/realm-boot.sh
@@ -29,6 +29,6 @@ tar -xf $ROOT/assets/prebuilt/out.tar.bz2 -C $ROOT
 $ROOT/scripts/fvp-cca -bo -rmm=islet --use-prebuilt --rmm-log-level=error
 $ROOT/scripts/fvp-cca -ro -nw=linux --realm=linux -rmm=islet --no-telnet &
 
-sleep 480
+sleep 640
 
 check_result