diff --git a/srcpkgs/justbuild/template b/srcpkgs/justbuild/template
index 51a41c2b02b..d28e0d51a3b 100644
--- a/srcpkgs/justbuild/template
+++ b/srcpkgs/justbuild/template
@@ -17,10 +17,11 @@ checksum=0fe771914265d3edae0ee17daf2be48ed602e33a0cd1b0d04d822c0b8cb488a4
 conflicts="just>=0"
 nocross="not supported by bootstrapping"
 
-CFLAGS="-Wno-deprecated-declarations"
-CXXFLAGS="-Wno-deprecated-declarations"
+CFLAGS="-Wno-error -Wno-deprecated-declarations"
+CXXFLAGS="-Wno-error -Wno-deprecated-declarations"
 
 do_build() {
+	rm -rf just-work
 	mkdir -p just-work
 	export JUST_BUILD_CONF=$(jo \
 		AR=/usr/bin/ar \
@@ -43,6 +44,8 @@ do_build() {
 		google_apis \
 		protobuf
 	)
+	sed -i "s/TaskSystem[(][0-9]*[)]/TaskSystem($XBPS_MAKEJOBS)/" \
+		justbuild-${version}/bin/parallel-bootstrap-traverser.py
 
 	PACKAGE=YES LOCALBASE=/usr python3 \
 		justbuild-${version}/bin/bootstrap.py \