diff --git a/zmq.c b/zmq.c
index 73d453f..40136e1 100644
--- a/zmq.c
+++ b/zmq.c
@@ -33,7 +33,10 @@
 #define MT_ZMQ_CONTEXT "MT_ZMQ_CONTEXT"
 #define MT_ZMQ_SOCKET  "MT_ZMQ_SOCKET"
 
-typedef struct { void *ptr; } zmq_ptr;
+typedef struct {
+    void *ptr;
+    int should_free;
+} zmq_ptr;
 
 static int Lzmq_version(lua_State *L)
 {
@@ -66,16 +69,35 @@ static int Lzmq_version(lua_State *L)
 
 static int Lzmq_init(lua_State *L)
 {
-    int io_threads = luaL_checkint(L, 1);
     zmq_ptr *ctx = lua_newuserdata(L, sizeof(zmq_ptr));
+    luaL_getmetatable(L, MT_ZMQ_CONTEXT);
+    lua_setmetatable(L, -2);
+
+    if (lua_islightuserdata(L, 1)) {
+        // Treat a light userdata as a raw ZMQ context object, which
+        // we'll silently wrap.  (And we won't automatically call term
+        // on it.)
+
+        ctx->ptr = lua_touserdata(L, 1);
+        ctx->should_free = 0;
+        return 1;
+    }
+
+    int io_threads = luaL_checkint(L, 1);
+
     ctx->ptr = zmq_init(io_threads);
 
     if (!ctx->ptr) {
         zmq_return_error();
     }
 
-    luaL_getmetatable(L, MT_ZMQ_CONTEXT);
-    lua_setmetatable(L, -2);
+    // toboolean defaults to false, but we want a missing param #2
+    // to mean true
+    if (lua_isnil(L, 2)) {
+        ctx->should_free = 1;
+    } else {
+        ctx->should_free = lua_toboolean(L, 2);
+    }
 
     return 1;
 }
@@ -97,6 +119,23 @@ static int Lzmq_term(lua_State *L)
     return 1;
 }
 
+static int Lzmq_ctx_gc(lua_State *L)
+{
+    zmq_ptr *ctx = luaL_checkudata(L, 1, MT_ZMQ_CONTEXT);
+    if (ctx->should_free) {
+        return Lzmq_term(L);
+    } else {
+        return 0;
+    }
+}
+
+static int Lzmq_ctx_lightuserdata(lua_State *L)
+{
+    zmq_ptr *ctx = luaL_checkudata(L, 1, MT_ZMQ_CONTEXT);
+    lua_pushlightuserdata(L, ctx->ptr);
+    return 1;
+}
+
 static int Lzmq_socket(lua_State *L)
 {
     zmq_ptr *ctx = luaL_checkudata(L, 1, MT_ZMQ_CONTEXT);
@@ -338,7 +377,8 @@ static const luaL_reg zmqlib[] = {
 };
 
 static const luaL_reg ctxmethods[] = {
-    {"__gc",       Lzmq_term},
+    {"__gc",       Lzmq_ctx_gc},
+    {"lightuserdata", Lzmq_ctx_lightuserdata},
     {"term",       Lzmq_term}, 
     {"socket",     Lzmq_socket},
     {NULL,         NULL}