diff --git a/arch/z16/src/z16f/Kconfig b/arch/z16/src/z16f/Kconfig
index 56067cae663..1a958cebb91 100644
--- a/arch/z16/src/z16f/Kconfig
+++ b/arch/z16/src/z16f/Kconfig
@@ -36,4 +36,21 @@ config Z16F_ESPI_REGDEBUG
 	depends on DEBUG_FEATURES
 
 endmenu # Z16F ESPI Configuration
+
+# The ZiLOG ZDS-II Windows toolchain is the only toolchain available for
+# the ZNeo.
+#
+
+choice
+	prompt "ZDS-II Toolchain version"
+	default Z16F_ZDSII_V521
+
+config Z16F_ZDSII_V501
+	bool "ZDS-II 5.0.1"
+
+config Z16F_ZDSII_V521
+	bool "ZDS-II 5.2.1"
+
+endchoice # ZDS-II Toolchain version
+
 endif # ARCH_CHIP_Z16F
diff --git a/configs/z16f2800100zcog/scripts/Make.defs b/configs/z16f2800100zcog/scripts/Make.defs
index e8f784ab4cf..fd896c438cb 100644
--- a/configs/z16f2800100zcog/scripts/Make.defs
+++ b/configs/z16f2800100zcog/scripts/Make.defs
@@ -36,19 +36,28 @@
 include $(TOPDIR)/.config
 include $(TOPDIR)/tools/Config.mk
 
-# These are the directories where the ZDS-II toolchain is installed.  NOTE
-# that short 8.3 path names are used in order to avoid spaces.  On my machine
-# I have:
+# These are the default directories where the ZDS-II toolchain is installed.
+# NOTE that short 8.3 path names are used in order to avoid spaces.  On my
+# machine I have:
 #
-# C:\PROGRA~1\ = C:\Profram Files\
-# C:\PROGRA~2\ = C:\Program Files (x86)\
+# Versions 5.0.1
+#   C:\PROGRA~1\ = C:\Program Files\
+#   C:\PROGRA~2\ = C:\Program Files (x86)\
 #
 # Your PC may be configured differently.
+#
+# Version 5.2.1, the default install location is C:\ZiLOG
 
-ZDSVERSION = 5.0.1
+ifeq ($(CONFIG_Z16F_ZDSII_V511),y)
+INSTALLROOT = C:/PROGRA~2/ZiLOG
+ZDSVERSION := 5.0.1
+else ifeq ($(CONFIG_Z16F_ZDSII_V521),y)
+INSTALLROOT = C:/ZiLOG
+ZDSVERSION := 5.2.1
+endif
 
 ifeq ($(CONFIG_WINDOWS_NATIVE),y)
-  ZDSINSTALLDIR = C:/PROGRA~2/ZiLOG/ZDSII_ZNEO_$(ZDSVERSION)
+  ZDSINSTALLDIR = $(INSTALLROOT)/ZiLOG/ZDSII_ZNEO_$(ZDSVERSION)
   INSTALLDIR = ${shell echo $(ZDSINSTALLDIR)| sed -e "s/\//\\/g"}
   ZDSBINDIR = $(INSTALLDIR)\bin
   ZDSSTDINCDIR = $(INSTALLDIR)\include\std
@@ -64,7 +73,7 @@ ifeq ($(CONFIG_WINDOWS_NATIVE),y)
   ARCHUSRINCLUDES = -usrinc:.
 else
   WINTOOL = y
-  ZDSINSTALLDIR = C:/PROGRA~2/ZiLOG/ZDSII_ZNEO_$(ZDSVERSION)
+  ZDSINSTALLDIR = $(INSTALLROOT)/ZiLOG/ZDSII_ZNEO_$(ZDSVERSION)
   INSTALLDIR = ${shell cygpath -u "$(ZDSINSTALLDIR)"}
   ZDSBINDIR = $(INSTALLDIR)/bin
   ZDSSTDINCDIR = $(INSTALLDIR)/include/std