diff --git a/lib/Makefile b/lib/Makefile
index 031c1b46bde6..aae401e0c76a 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -129,7 +129,7 @@ SUBDIR_DEPEND_libarchive= libz libbz2 libexpat liblzma libmd
 SUBDIR_DEPEND_libatm= libmd
 SUBDIR_DEPEND_libauditdm= libbsm
 SUBDIR_DEPEND_libbsnmp= ${_libnetgraph}
-SUBDIR_DEPEND_libc++= libcxxrt
+SUBDIR_DEPEND_libc++:= libcxxrt
 SUBDIR_DEPEND_libc= libcompiler_rt
 SUBDIR_DEPEND_libcam= libsbuf
 SUBDIR_DEPEND_libcapsicum= libnv
@@ -148,7 +148,7 @@ SUBDIR_DEPEND_libpjdlog= libutil
 SUBDIR_DEPEND_libprocstat= libkvm libutil
 SUBDIR_DEPEND_libradius= libmd
 SUBDIR_DEPEND_libsmb= libkiconv
-SUBDIR_DEPEND_libstdc++= msun
+SUBDIR_DEPEND_libstdc++:= msun
 SUBDIR_DEPEND_libtacplus= libmd
 SUBDIR_DEPEND_libulog= libmd
 SUBDIR_DEPEND_libunbound= ${_libldns}