diff --git a/etc/mtree/BSD.debug.dist b/etc/mtree/BSD.debug.dist
index 4ca8413103a..3d8fcb7bc2d 100644
--- a/etc/mtree/BSD.debug.dist
+++ b/etc/mtree/BSD.debug.dist
@@ -29,7 +29,7 @@
             ..
             lib
                 clang
-                    3.9.1
+                    4.0.0
                         lib
                             freebsd
                             ..
diff --git a/etc/mtree/BSD.usr.dist b/etc/mtree/BSD.usr.dist
index 70d652e0281..2f1ad77e4c5 100644
--- a/etc/mtree/BSD.usr.dist
+++ b/etc/mtree/BSD.usr.dist
@@ -19,7 +19,7 @@
         aout
         ..
         clang
-            3.9.1
+            4.0.0
                 include
                     sanitizer
                     ..
diff --git a/lib/clang/headers/Makefile b/lib/clang/headers/Makefile
index 5036a17a0ab..be03a70e2c6 100644
--- a/lib/clang/headers/Makefile
+++ b/lib/clang/headers/Makefile
@@ -4,7 +4,7 @@
 
 .PATH:		${CLANG_SRCS}/lib/Headers
 
-INCSDIR=	${LIBDIR}/clang/3.9.1/include
+INCSDIR=	${LIBDIR}/clang/4.0.0/include
 
 GENINCS+=	arm_neon.h
 
diff --git a/lib/libclang_rt/Makefile.inc b/lib/libclang_rt/Makefile.inc
index 47cd21b5cf7..08ab48f4677 100644
--- a/lib/libclang_rt/Makefile.inc
+++ b/lib/libclang_rt/Makefile.inc
@@ -7,7 +7,7 @@ CRTSRC=		${SRCTOP}/contrib/compiler-rt
 
 .PATH:		${CRTSRC}/lib
 
-CLANGDIR=	/usr/lib/clang/3.9.1
+CLANGDIR=	/usr/lib/clang/4.0.0
 LIBDIR=		${CLANGDIR}/lib/freebsd
 
 NO_PIC=