diff --git a/debian-bullseye-titan/Dockerfile b/debian-bullseye-titan/Dockerfile
index 0b1fbdac..1c224565 100644
--- a/debian-bullseye-titan/Dockerfile
+++ b/debian-bullseye-titan/Dockerfile
@@ -65,7 +65,7 @@ ADD	https://git.osmocom.org/osmo-ttcn3-hacks/plain/deps/Makefile /tmp/deps-Makef
 RUN	if ! diff -q /tmp/deps-Makefile /osmo-ttcn3-hacks/deps/Makefile; then \
 		cd /osmo-ttcn3-hacks && \
 		git pull && \
-		make deps; \
+		make -j8 deps; \
 	fi
 
 ADD	ttcn3-docker-prepare.sh /usr/local/bin/ttcn3-docker-prepare
diff --git a/debian-bullseye-titan/ttcn3-docker-prepare.sh b/debian-bullseye-titan/ttcn3-docker-prepare.sh
index e4144e20..c2b28b93 100755
--- a/debian-bullseye-titan/ttcn3-docker-prepare.sh
+++ b/debian-bullseye-titan/ttcn3-docker-prepare.sh
@@ -29,7 +29,7 @@ git rev-parse HEAD
 # OSMO_TTCN3_BRANCH is different). The Dockerfile does the initial 'make deps'
 # and downloads /tmp/deps-Makefile.
 if ! diff -q /tmp/deps-Makefile deps/Makefile; then
-	make deps
+	make -j8 deps
 fi
 
 # Link start/stop scripts to /