diff --git a/poky/meta-poky/conf/distro/poky-altcfg.conf b/poky/meta-poky/conf/distro/poky-altcfg.conf
index 177bf8d..fbfabec 100644
--- a/poky/meta-poky/conf/distro/poky-altcfg.conf
+++ b/poky/meta-poky/conf/distro/poky-altcfg.conf
@@ -10,6 +10,6 @@
 
 INIT_MANAGER ?= "systemd"
 # systemd isn't suitable with musl
-INIT_MANAGER_libc-musl ?= "sysvinit"
+INIT_MANAGER:libc-musl ?= "sysvinit"
 
 require conf/distro/include/poky-distro-alt-test-config.inc