Index: Mk/bsd.port.mk
===================================================================
--- Mk/bsd.port.mk
+++ Mk/bsd.port.mk
@@ -1053,6 +1053,11 @@
 # make -C /usr/ports/category/port/.
 .CURDIR:=		${.CURDIR:tA}
 
+# Ensure .CURDIR doesn't contain a colon, which breaks makefile targets
+.if ${.CURDIR:S/:/\:/g} != ${.CURDIR}
+.error The current directory path contains ':', that are not supported
+.endif
+
 # make sure bmake treats -V as expected
 .MAKE.EXPAND_VARIABLES= yes
 
Index: Mk/bsd.port.subdir.mk
===================================================================
--- Mk/bsd.port.subdir.mk
+++ Mk/bsd.port.subdir.mk
@@ -51,6 +51,11 @@
 # make -C /usr/ports/category/port/.
 .CURDIR:=		${.CURDIR:tA}
 
+# Ensure .CURDIR doesn't contain a colon, which breaks makefile targets
+.if ${.CURDIR:S/:/\:/g} != ${.CURDIR}
+.error The current directory path contains ':', that are not supported
+.endif
+
 .include "${PORTSDIR}/Mk/bsd.commands.mk"
 
 .MAIN: all