diff --git a/Makefile b/Makefile
index b9c78f6d..69abf7e9 100644
--- a/Makefile
+++ b/Makefile
@@ -12,7 +12,7 @@ DISTRO:=humble
 ARCH ?= unknown
 VERSION ?= unknown
 
-NUM_JOBS ?= $(or $(subst -j,,$(filter -j%,$(subst -j ,-j$(shell nproc),$(MAKEFLAGS)))),1)
+NUM_JOBS ?= $(or $(subst -j,,$(filter -j%,$(subst -j ,-j$(shell nproc),$(MAKEFLAGS) ))),1)
 
 DEFAULT_ROSDEP_PATH:=/etc/ros/rosdep