diff --git a/REQUIRE b/REQUIRE
index 9f5f639b..c99c2b85 100644
--- a/REQUIRE
+++ b/REQUIRE
@@ -1,7 +1,7 @@
 julia 0.7
 MbedTLS 0.4.3
 JSON 0.17
-ZMQ 0.6.0
+ZMQ 1.0.0
 Compat 0.69.0
 Conda 0.1.5
 SoftGlobalScope
diff --git a/src/heartbeat.jl b/src/heartbeat.jl
index 08838cc6..ab1dc3a9 100644
--- a/src/heartbeat.jl
+++ b/src/heartbeat.jl
@@ -18,5 +18,5 @@ end
 function start_heartbeat(sock)
     heartbeat_c = @cfunction(heartbeat_thread, Cvoid, (Ptr{Cvoid},))
     ccall(:uv_thread_create, Cint, (Ptr{Int}, Ptr{Cvoid}, Ptr{Cvoid}),
-          threadid, heartbeat_c, sock.data)
+          threadid, heartbeat_c, sock)
 end
diff --git a/src/init.jl b/src/init.jl
index f9316d02..8f3c61c4 100644
--- a/src/init.jl
+++ b/src/init.jl
@@ -21,7 +21,6 @@ function __init__()
 end
 
 # the following constants need to be initialized in init().
-const ctx = Ref{Context}()
 const publish = Ref{Socket}()
 const raw_input = Ref{Socket}()
 const requests = Ref{Socket}()
@@ -91,12 +90,11 @@ function init(args)
                                  profile["key"])
     end
 
-    ctx[] = Context()
-    publish[] = Socket(ctx[], PUB)
-    raw_input[] = Socket(ctx[], ROUTER)
-    requests[] = Socket(ctx[], ROUTER)
-    control[] = Socket(ctx[], ROUTER)
-    heartbeat[] = Socket(ctx[], ROUTER)
+    publish[] = Socket(PUB)
+    raw_input[] = Socket(ROUTER)
+    requests[] = Socket(ROUTER)
+    control[] = Socket(ROUTER)
+    heartbeat[] = Socket(ROUTER)
     bind(publish[], "$(profile["transport"])://$(profile["ip"]):$(profile["iopub_port"])")
     bind(requests[], "$(profile["transport"])://$(profile["ip"]):$(profile["shell_port"])")
     bind(control[], "$(profile["transport"])://$(profile["ip"]):$(profile["control_port"])")
diff --git a/src/msg.jl b/src/msg.jl
index 61f07650..6208d2ee 100644
--- a/src/msg.jl
+++ b/src/msg.jl
@@ -45,17 +45,17 @@ function send_ipython(socket, m::Msg)
     try
         @vprintln("SENDING ", m)
         for i in m.idents
-            send(socket, i, SNDMORE)
+            send(socket, i, more=true)
         end
-        send(socket, "<IDS|MSG>", SNDMORE)
+        send(socket, "<IDS|MSG>", more=true)
         header = json(m.header)
         parent_header = json(m.parent_header)
         metadata = json(m.metadata)
         content = json(m.content)
-        send(socket, hmac(header, parent_header, metadata, content), SNDMORE)
-        send(socket, header, SNDMORE)
-        send(socket, parent_header, SNDMORE)
-        send(socket, metadata, SNDMORE)
+        send(socket, hmac(header, parent_header, metadata, content), more=true)
+        send(socket, header, more=true)
+        send(socket, parent_header, more=true)
+        send(socket, metadata, more=true)
         send(socket, content)
     finally
         unlock(socket_locks[socket])
@@ -65,22 +65,20 @@ end
 function recv_ipython(socket)
     lock(socket_locks[socket])
     try
-        msg = recv(socket)
         idents = String[]
-        s = unsafe_string(msg)
+        s = recv(socket, String)
         @vprintln("got msg part $s")
         while s != "<IDS|MSG>"
             push!(idents, s)
-            msg = recv(socket)
-            s = unsafe_string(msg)
+            s = recv(socket, String)
             @vprintln("got msg part $s")
         end
-        signature = unsafe_string(recv(socket))
+        signature = recv(socket, String)
         request = Dict{String,Any}()
-        header = unsafe_string(recv(socket))
-        parent_header = unsafe_string(recv(socket))
-        metadata = unsafe_string(recv(socket))
-        content = unsafe_string(recv(socket))
+        header = recv(socket, String)
+        parent_header = recv(socket, String)
+        metadata = recv(socket, String)
+        content = recv(socket, String)
         if signature != hmac(header, parent_header, metadata, content)
             error("Invalid HMAC signature") # What should we do here?
         end