diff --git a/devel/llbuild/Makefile b/devel/llbuild/Makefile
--- a/devel/llbuild/Makefile
+++ b/devel/llbuild/Makefile
@@ -2,6 +2,7 @@
 DISTVERSIONPREFIX=	swift-DEVELOPMENT-
 DISTVERSION=		SNAPSHOT-2017-12-10
 DISTVERSIONSUFFIX=	-a
+PORTREVISION=		1
 CATEGORIES=		devel
 
 MAINTAINER=	jonathan@FreeBSD.org
@@ -14,7 +15,7 @@
 
 LIB_DEPENDS=	libsqlite3.so:databases/sqlite3
 
-USES=		cmake sbrk
+USES=		cmake
 
 USE_GITHUB=	yes
 GH_ACCOUNT=	apple
diff --git a/devel/llbuild/files/patch-include_llvm_Config_config.h b/devel/llbuild/files/patch-include_llvm_Config_config.h
new file mode 100644
--- /dev/null
+++ b/devel/llbuild/files/patch-include_llvm_Config_config.h
@@ -0,0 +1,23 @@
+--- include/llvm/Config/config.h.orig
++++ include/llvm/Config/config.h
+@@ -117,17 +117,17 @@
+ #define HAVE_MALLOC_ZONE_STATISTICS 1
+ 
+ /* Define to 1 if you have the `mallctl` function. */
+-/* #undef HAVE_MALLCTL */
++#define HAVE_MALLCTL 1
+ 
+ /* Define to 1 if you have a working `mmap' system call. */
+-#undef HAVE_MMAP
++#define HAVE_MMAP 1
+ 
+ /* Define if mmap() uses MAP_ANONYMOUS to map anonymous pages, or undefine if
+    it uses MAP_ANON */
+ #undef HAVE_MMAP_ANONYMOUS
+ 
+ /* Define if mmap() can map files into memory */
+-#undef HAVE_MMAP_FILE
++#define HAVE_MMAP_FILE 1
+ 
+ /* Define to 1 if you have the `posix_spawn' function. */
+ #define HAVE_POSIX_SPAWN 1