diff --git a/lib/libcompiler_rt/Makefile.inc b/lib/libcompiler_rt/Makefile.inc
index 44a963ff9ed1..30608826b8fa 100644
--- a/lib/libcompiler_rt/Makefile.inc
+++ b/lib/libcompiler_rt/Makefile.inc
@@ -225,9 +225,8 @@ SRCS+=		switchu8.S
 SRCS+=		sync_synchronize.S
 .endif
 
-# GCC-6.3 on mips32 requires bswap32 built-in.
-.if ${MACHINE_CPUARCH} == "mips"
+# On some archs GCC-6.3 requires bswap32 built-in.
+.if ${MACHINE_CPUARCH} == "mips" || ${MACHINE_CPUARCH} == "sparc64"
 SRCS+=		bswapdi2.c
 SRCS+=		bswapsi2.c
 .endif
-