diff --git a/Makefile b/Makefile
index 40c22434..327151a7 100644
--- a/Makefile
+++ b/Makefile
@@ -26,11 +26,12 @@ ABIVER=  5.1
 # the paths in src/luaconf.h, too. Note: PREFIX must be an absolute path!
 #
 export PREFIX= /usr/local
+export MULTILIB= lib
 ##############################################################################
 
 DPREFIX= $(DESTDIR)$(PREFIX)
 INSTALL_BIN=   $(DPREFIX)/bin
-INSTALL_LIB=   $(DPREFIX)/lib
+INSTALL_LIB=   $(DPREFIX)/$(MULTILIB)
 INSTALL_SHARE= $(DPREFIX)/share
 INSTALL_INC=   $(DPREFIX)/include/luajit-$(MAJVER).$(MINVER)
 
@@ -74,7 +75,8 @@ INSTALL_X= install -m 0755
 INSTALL_F= install -m 0644
 UNINSTALL= $(RM)
 LDCONFIG= ldconfig -n
-SED_PC= sed -e "s|^prefix=.*|prefix=$(PREFIX)|"
+SED_PC= sed -e "s|^prefix=.*|prefix=$(PREFIX)|" \
+            -e "s|^multilib=.*|multilib=$(MULTILIB)|"
 
 FILE_T= luajit
 FILE_A= libluajit.a
diff --git a/doc/install.html b/doc/install.html
index faf19c43..b7bf75ce 100644
--- a/doc/install.html
+++ b/doc/install.html
@@ -565,9 +565,11 @@ for a regular distribution build:
 <ul>
 <li><tt>PREFIX</tt> overrides the installation path and should usually
 be set to <tt>/usr</tt>. Setting this also changes the module paths and
-the <tt>-rpath</tt> of the shared library.</li>
+the paths needed to locate the shared library.</li>
 <li><tt>DESTDIR</tt> is an absolute path which allows you to install
 to a shadow tree instead of the root tree of the build system.</li>
+<li><tt>MULTILIB</tt> sets the architecture-specific library path component
+for multilib systems. The default is <tt>lib</tt>.</li>
 <li>Have a look at the top-level <tt>Makefile</tt> and <tt>src/Makefile</tt>
 for additional variables to tweak. The following variables <em>may</em> be
 overridden, but it's <em>not</em> recommended, except for special needs
diff --git a/dynasm/dasm_x86.lua b/dynasm/dasm_x86.lua
index 1f0981f3..07ddd98d 100644
--- a/dynasm/dasm_x86.lua
+++ b/dynasm/dasm_x86.lua
@@ -1040,7 +1040,7 @@ local map_op = {
   -- ED: *in Rdw,dx
   -- EE: *out dx,Rb
   -- EF: *out dx,Rdw
-  -- F0: *lock
+  lock_0 =	"F0",
   int1_0 =	"F1",
   repne_0 =	"F2",
   repnz_0 =	"F2",
diff --git a/etc/luajit.pc b/etc/luajit.pc
index d3c7d9a2..5ec2c35c 100644
--- a/etc/luajit.pc
+++ b/etc/luajit.pc
@@ -6,13 +6,14 @@ version=${majver}.${minver}.${relver}-alpha
 abiver=5.1
 
 prefix=/usr/local
+multilib=lib
 exec_prefix=${prefix}
-libdir=${exec_prefix}/lib
+libdir=${exec_prefix}/${multilib}
 libname=luajit-${abiver}
 includedir=${prefix}/include/luajit-${majver}.${minver}
 
 INSTALL_LMOD=${prefix}/share/lua/${abiver}
-INSTALL_CMOD=${prefix}/lib/lua/${abiver}
+INSTALL_CMOD=${prefix}/${multilib}/lua/${abiver}
 
 Name: LuaJIT
 Description: Just-in-time compiler for Lua
diff --git a/src/Makefile b/src/Makefile
index 94bc0fd2..441feffb 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -185,9 +185,10 @@ TARGET_LD= $(CROSS)$(CC)
 TARGET_AR= $(CROSS)ar rcus
 TARGET_STRIP= $(CROSS)strip
 
+TARGET_LIBPATH= $(or $(PREFIX),/usr/local)/$(or $(MULTILIB),lib)
 TARGET_SONAME= libluajit-$(ABIVER).so.$(MAJVER)
 TARGET_DYLIBNAME= libluajit-$(ABIVER).$(MAJVER).dylib
-TARGET_DYLIBPATH= $(or $(PREFIX),/usr/local)/lib/$(TARGET_DYLIBNAME)
+TARGET_DYLIBPATH= $(TARGET_LIBPATH)/$(TARGET_DYLIBNAME)
 TARGET_DLLNAME= lua$(NODOTABIVER).dll
 TARGET_XSHLDFLAGS= -shared -fPIC -Wl,-soname,$(TARGET_SONAME)
 TARGET_DYNXLDOPTS=
@@ -246,12 +247,18 @@ TARGET_ARCH+= $(patsubst %,-DLUAJIT_TARGET=LUAJIT_ARCH_%,$(TARGET_LJARCH))
 
 ifneq (,$(PREFIX))
 ifneq (/usr/local,$(PREFIX))
-  TARGET_XCFLAGS+= -DLUA_XROOT=\"$(PREFIX)/\"
+  TARGET_XCFLAGS+= -DLUA_ROOT=\"$(PREFIX)\"
   ifneq (/usr,$(PREFIX))
-    TARGET_DYNXLDOPTS= -Wl,-rpath,$(PREFIX)/lib
+    TARGET_DYNXLDOPTS= -Wl,-rpath,$(TARGET_LIBPATH)
   endif
 endif
 endif
+ifneq (,$(MULTILIB))
+  TARGET_XCFLAGS+= -DLUA_MULTILIB=\"$(MULTILIB)\"
+endif
+ifneq (,$(LMULTILIB))
+  TARGET_XCFLAGS+= -DLUA_LMULTILIB=\"$(LMULTILIB)\"
+endif
 
 ##############################################################################
 # System detection.
diff --git a/src/luaconf.h b/src/luaconf.h
index d283233d..d5f2d0f5 100644
--- a/src/luaconf.h
+++ b/src/luaconf.h
@@ -23,26 +23,40 @@
   ".\\?.dll;" LUA_CDIR"?.dll;" LUA_CDIR"loadall.dll"
 #else
 /*
-** Note to distribution maintainers: do NOT patch the following line!
+** Note to distribution maintainers: do NOT patch the following lines!
 ** Please read ../doc/install.html#distro and pass PREFIX=/usr instead.
 */
-#define LUA_ROOT	"/usr/local/"
-#define LUA_LDIR	LUA_ROOT "share/lua/5.1/"
-#define LUA_CDIR	LUA_ROOT "lib/lua/5.1/"
-#ifdef LUA_XROOT
-#define LUA_JDIR	LUA_XROOT "share/luajit-2.1.0-alpha/"
-#define LUA_XPATH \
-  ";" LUA_XROOT "share/lua/5.1/?.lua;" LUA_XROOT "share/lua/5.1/?/init.lua"
-#define LUA_XCPATH	LUA_XROOT "lib/lua/5.1/?.so;"
-#else
-#define LUA_JDIR	LUA_ROOT "share/luajit-2.1.0-alpha/"
-#define LUA_XPATH
-#define LUA_XCPATH
+#ifndef LUA_MULTILIB
+#define LUA_MULTILIB	"lib"
 #endif
-#define LUA_PATH_DEFAULT \
-  "./?.lua;" LUA_JDIR"?.lua;" LUA_LDIR"?.lua;" LUA_LDIR"?/init.lua" LUA_XPATH
-#define LUA_CPATH_DEFAULT \
-  "./?.so;" LUA_CDIR"?.so;" LUA_XCPATH LUA_CDIR"loadall.so"
+#ifndef LUA_LMULTILIB
+#define LUA_LMULTILIB	"lib"
+#endif
+#define LUA_LROOT	"/usr/local"
+#define LUA_LUADIR	"/lua/5.1/"
+#define LUA_LJDIR	"/luajit-2.1.0-alpha/"
+
+#ifdef LUA_ROOT
+#define LUA_JROOT	LUA_ROOT
+#define LUA_RLDIR	LUA_ROOT "/share" LUA_LUADIR
+#define LUA_RCDIR	LUA_ROOT "/" LUA_MULTILIB LUA_LUADIR
+#define LUA_RLPATH	";" LUA_RLDIR "?.lua;" LUA_RLDIR "?/init.lua"
+#define LUA_RCPATH	";" LUA_RCDIR "?.so"
+#else
+#define LUA_JROOT	LUA_LROOT
+#define LUA_RLPATH
+#define LUA_RCPATH
+#endif
+
+#define LUA_JPATH	";" LUA_JROOT "/share" LUA_LJDIR "?.lua"
+#define LUA_LLDIR	LUA_LROOT "/share" LUA_LUADIR
+#define LUA_LCDIR	LUA_LROOT "/" LUA_LMULTILIB LUA_LUADIR
+#define LUA_LLPATH	";" LUA_LLDIR "?.lua;" LUA_LLDIR "?/init.lua"
+#define LUA_LCPATH1	";" LUA_LCDIR "?.so"
+#define LUA_LCPATH2	";" LUA_LCDIR "loadall.so"
+
+#define LUA_PATH_DEFAULT	"./?.lua" LUA_JPATH LUA_LLPATH LUA_RLPATH
+#define LUA_CPATH_DEFAULT	"./?.so" LUA_LCPATH1 LUA_RCPATH LUA_LCPATH2
 #endif
 
 /* Environment variable names for path overrides and initialization code. */