diff --git a/conf/machine/baremetal-riscv32nf.conf b/conf/machine/baremetal-riscv32nf.conf
index c568b2b..4827169 100644
--- a/conf/machine/baremetal-riscv32nf.conf
+++ b/conf/machine/baremetal-riscv32nf.conf
@@ -6,8 +6,8 @@ DEFAULTTUNE = "riscv32nf"
 require conf/machine/include/qemu.inc
 require conf/machine/include/riscv/tune-riscv.inc
 
-PREFERRED_VERSION:openocd-native = "riscv"
-PREFERRED_VERSION:openocd = "riscv"
+PREFERRED_VERSION_openocd-native = "riscv"
+PREFERRED_VERSION_openocd = "riscv"
 
 # qemuboot options
 QB_MACHINE = "-machine virt"