diff --git a/lib/Makefile b/lib/Makefile
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -180,7 +180,8 @@
 SUBDIR.${MK_STATS}+=	libstats
 
 # The libraries under libclang_rt can only be built by clang.
-.if ${COMPILER_TYPE} == "clang" && ${MK_CLANG} != "no"
+.if (${COMPILER_TYPE} == "clang" || make(clean) || make(cleandir)) && \
+    ${MK_CLANG} != "no"
 _libclang_rt=	libclang_rt
 .elif (${MK_ASAN} != "no" || ${MK_UBSAN} != "no") && make(all)
 .error Requested build with sanitizers but cannot build runtime libraries!