diff --git a/lib/libc/Makefile b/lib/libc/Makefile
--- a/lib/libc/Makefile
+++ b/lib/libc/Makefile
@@ -109,10 +109,7 @@
 .include "${LIBC_SRCTOP}/net/Makefile.inc"
 .include "${LIBC_SRCTOP}/nls/Makefile.inc"
 .include "${LIBC_SRCTOP}/posix1e/Makefile.inc"
-.if ${LIBC_ARCH} != "aarch64" && \
-    ${LIBC_ARCH} != "amd64" && \
-    ${LIBC_ARCH} != "powerpc64" && \
-    ${LIBC_ARCH} != "riscv"
+.if ${MACHINE_ABI:Mlong32}
 .include "${LIBC_SRCTOP}/quad/Makefile.inc"
 .endif
 .include "${LIBC_SRCTOP}/regex/Makefile.inc"