diff --git a/stand/i386/btx/lib/Makefile b/stand/i386/btx/lib/Makefile
index 2988f4297660..a9e2e4350a55 100644
--- a/stand/i386/btx/lib/Makefile
+++ b/stand/i386/btx/lib/Makefile
@@ -4,7 +4,7 @@
 
 PROG=	crt0.o
 INTERNALPROG=
-SRCS=	btxcsu.S btxsys.s btxv86.s
+SRCS=	btxcsu.S btxsys.S btxv86.S
 CFLAGS+=-I${BOOTSRC}/i386/common
 LDFLAGS+=-Wl,-r
 
diff --git a/stand/i386/btx/lib/btxsys.s b/stand/i386/btx/lib/btxsys.S
similarity index 100%
rename from stand/i386/btx/lib/btxsys.s
rename to stand/i386/btx/lib/btxsys.S
diff --git a/stand/i386/btx/lib/btxv86.s b/stand/i386/btx/lib/btxv86.S
similarity index 100%
rename from stand/i386/btx/lib/btxv86.s
rename to stand/i386/btx/lib/btxv86.S