diff --git a/src/wpool_process.erl b/src/wpool_process.erl
index 886c853..9105e6e 100644
--- a/src/wpool_process.erl
+++ b/src/wpool_process.erl
@@ -18,9 +18,33 @@
 
 -behaviour(gen_server).
 
+%% Taken from gen_server OTP
+-record(callback_cache,
+        {module :: module(),
+         handle_call ::
+             fun((Request :: term(), From :: from(), State :: term()) ->
+                     {reply, Reply :: term(), NewState :: term()} |
+                     {reply,
+                      Reply :: term(),
+                      NewState :: term(),
+                      timeout() | hibernate | {continue, term()}} |
+                     {noreply, NewState :: term()} |
+                     {noreply, NewState :: term(), timeout() | hibernate | {continue, term()}} |
+                     {stop, Reason :: term(), Reply :: term(), NewState :: term()} |
+                     {stop, Reason :: term(), NewState :: term()}),
+         handle_cast ::
+             fun((Request :: term(), State :: term()) ->
+                     {noreply, NewState :: term()} |
+                     {noreply, NewState :: term(), timeout() | hibernate | {continue, term()}} |
+                     {stop, Reason :: term(), NewState :: term()}),
+         handle_info ::
+             fun((Info :: timeout | term(), State :: term()) ->
+                     {noreply, NewState :: term()} |
+                     {noreply, NewState :: term(), timeout() | hibernate | {continue, term()}} |
+                     {stop, Reason :: term(), NewState :: term()})}).
 -record(state,
         {name :: atom(),
-         mod :: atom(),
+         mod :: #callback_cache{},
          state :: term(),
          options ::
              #{time_checker := atom(),
@@ -103,13 +127,14 @@ get_state(#state{state = State}) ->
 init({Name, Mod, InitArgs, LOptions}) ->
     Options = maps:from_list(LOptions),
     wpool_process_callbacks:notify(handle_init_start, Options, [Name]),
+    CbCache = create_callback_cache(Mod),
     case Mod:init(InitArgs) of
         {ok, ModState} ->
             ok = notify_queue_manager(new_worker, Name, Options),
             wpool_process_callbacks:notify(handle_worker_creation, Options, [Name]),
             {ok,
              #state{name = Name,
-                    mod = Mod,
+                    mod = CbCache,
                     state = ModState,
                     options = Options}};
         {ok, ModState, NextStep} ->
@@ -117,7 +142,7 @@ init({Name, Mod, InitArgs, LOptions}) ->
             wpool_process_callbacks:notify(handle_worker_creation, Options, [Name]),
             {ok,
              #state{name = Name,
-                    mod = Mod,
+                    mod = CbCache,
                     state = ModState,
                     options = Options},
              NextStep};
@@ -130,30 +155,42 @@ init({Name, Mod, InitArgs, LOptions}) ->
 %% @private
 -spec terminate(atom(), state()) -> term().
 terminate(Reason, State) ->
-    #state{mod = Mod,
+    #state{mod = #callback_cache{module = Mod},
            state = ModState,
            name = Name,
            options = Options} =
         State,
     ok = notify_queue_manager(worker_dead, Name, Options),
     wpool_process_callbacks:notify(handle_worker_death, Options, [Name, Reason]),
-    Mod:terminate(Reason, ModState).
+    case erlang:function_exported(Mod, terminate, 2) of
+        true ->
+            Mod:terminate(Reason, ModState);
+        _ ->
+            ok
+    end.
 
 %% @private
--spec code_change(string(), state(), any()) -> {ok, state()} | {error, term()}.
-code_change(OldVsn, State, Extra) ->
-    case (State#state.mod):code_change(OldVsn, State#state.state, Extra) of
-        {ok, NewState} ->
-            {ok, State#state{state = NewState}};
-        Error ->
-            {error, Error}
+-spec code_change(string() | {down, string()}, state(), any()) ->
+                     {ok, state()} | {error, term()}.
+code_change(OldVsn, #state{mod = #callback_cache{module = Mod}} = State, Extra) ->
+    case erlang:function_exported(Mod, code_change, 3) of
+        true ->
+            case Mod:code_change(OldVsn, State#state.state, Extra) of
+                {ok, NewState} ->
+                    {ok, State#state{state = NewState}};
+                {error, Error} ->
+                    {error, Error}
+            end;
+        _ ->
+            {ok, State}
     end.
 
 %% @private
 -spec handle_info(any(), state()) ->
                      {noreply, state()} | {noreply, state(), next_step()} | {stop, term(), state()}.
-handle_info(Info, State) ->
-    try (State#state.mod):handle_info(Info, State#state.state) of
+handle_info(Info, #state{mod = CbCache} = State) ->
+    #callback_cache{module = Mod, handle_info = HandleInfo} = CbCache,
+    try HandleInfo(Info, State#state.state) of
         {noreply, NewState} ->
             {noreply, State#state{state = NewState}};
         {noreply, NewState, NextStep} ->
@@ -161,6 +198,13 @@ handle_info(Info, State) ->
         {stop, Reason, NewState} ->
             {stop, Reason, State#state{state = NewState}}
     catch
+        error:undef:Stacktrace ->
+            case erlang:function_exported(Mod, handle_info, 2) of
+                false ->
+                    {noreply, State};
+                true ->
+                    erlang:raise(error, undef, Stacktrace)
+            end;
         _:{noreply, NewState} ->
             {noreply, State#state{state = NewState}};
         _:{noreply, NewState, NextStep} ->
@@ -174,8 +218,8 @@ handle_info(Info, State) ->
                          {noreply, state()} |
                          {noreply, state(), next_step()} |
                          {stop, term(), state()}.
-handle_continue(Continue, State) ->
-    try (State#state.mod):handle_continue(Continue, State#state.state) of
+handle_continue(Continue, #state{mod = #callback_cache{module = Mod}} = State) ->
+    try Mod:handle_continue(Continue, State#state.state) of
         {noreply, NewState} ->
             {noreply, State#state{state = NewState}};
         {noreply, NewState, NextStep} ->
@@ -193,7 +237,7 @@ handle_continue(Continue, State) ->
 
 %% @private
 -spec format_status(gen_server:format_status()) -> gen_server:format_status().
-format_status(#{state := #state{mod = Mod}} = Status) ->
+format_status(#{state := #state{mod = #callback_cache{module = Mod}}} = Status) ->
     case erlang:function_exported(Mod, format_status, 1) of
         false ->
             Status;
@@ -207,11 +251,12 @@ format_status(#{state := #state{mod = Mod}} = Status) ->
 %% @private
 -spec handle_cast(term(), state()) ->
                      {noreply, state()} | {noreply, state(), next_step()} | {stop, term(), state()}.
-handle_cast(Cast, #state{options = Options} = State) ->
+handle_cast(Cast, #state{mod = CbCache, options = Options} = State) ->
+    #callback_cache{handle_cast = HandleCast} = CbCache,
     Task = wpool_utils:task_init({cast, Cast}, Options),
     ok = notify_queue_manager(worker_busy, State#state.name, Options),
     Reply =
-        try (State#state.mod):handle_cast(Cast, State#state.state) of
+        try HandleCast(Cast, State#state.state) of
             {noreply, NewState} ->
                 {noreply, State#state{state = NewState}};
             {noreply, NewState, NextStep} ->
@@ -238,11 +283,12 @@ handle_cast(Cast, #state{options = Options} = State) ->
                      {noreply, state(), next_step()} |
                      {stop, term(), term(), state()} |
                      {stop, term(), state()}.
-handle_call(Call, From, #state{options = Options} = State) ->
+handle_call(Call, From, #state{mod = CbCache, options = Options} = State) ->
+    #callback_cache{handle_call = HandleCall} = CbCache,
     Task = wpool_utils:task_init({call, Call}, Options),
     ok = notify_queue_manager(worker_busy, State#state.name, Options),
     Reply =
-        try (State#state.mod):handle_call(Call, From, State#state.state) of
+        try HandleCall(Call, From, State#state.state) of
             {noreply, NewState} ->
                 {noreply, State#state{state = NewState}};
             {noreply, NewState, NextStep} ->
@@ -277,3 +323,9 @@ notify_queue_manager(Function, Name, #{queue_manager := QueueManager}) ->
     wpool_queue_manager:Function(QueueManager, Name);
 notify_queue_manager(_, _, _) ->
     ok.
+
+create_callback_cache(Mod) ->
+    #callback_cache{module = Mod,
+                    handle_call = fun Mod:handle_call/3,
+                    handle_cast = fun Mod:handle_cast/2,
+                    handle_info = fun Mod:handle_info/2}.
diff --git a/test/crashy_server.erl b/test/crashy_server.erl
index e3c30e0..90ec009 100644
--- a/test/crashy_server.erl
+++ b/test/crashy_server.erl
@@ -44,6 +44,8 @@ code_change(_OldVsn, State, _Extra) ->
 -spec handle_info(timeout | Info, term()) -> {noreply, timeout} | Info.
 handle_info(timeout, _State) ->
     {noreply, timeout};
+handle_info(undef, _State) ->
+    erlang:error(undef);
 handle_info(Info, _State) ->
     Info.
 
diff --git a/test/wpool_process_SUITE.erl b/test/wpool_process_SUITE.erl
index 7638452..1e63f8b 100644
--- a/test/wpool_process_SUITE.erl
+++ b/test/wpool_process_SUITE.erl
@@ -24,7 +24,7 @@
 -export([all/0]).
 -export([init_per_suite/1, end_per_suite/1, init_per_testcase/2, end_per_testcase/2]).
 -export([init/1, init_timeout/1, info/1, cast/1, send_request/1, call/1, continue/1,
-         format_status/1, no_format_status/1, stop/1]).
+         handle_info_missing/1, handle_info_fails/1, format_status/1, no_format_status/1, stop/1]).
 -export([pool_restart_crash/1, pool_norestart_crash/1, complete_coverage/1]).
 
 -spec all() -> [atom()].
@@ -173,6 +173,21 @@ continue(_Config) ->
 
     {comment, []}.
 
+-spec handle_info_missing(config()) -> {comment, []}.
+handle_info_missing(_Config) ->
+    %% sleepy_server does not implement handle_info/2
+    {ok, Pid} = wpool_process:start_link(?MODULE, sleepy_server, 1, []),
+    Pid ! test,
+    {comment, []}.
+
+-spec handle_info_fails(config()) -> {comment, []}.
+handle_info_fails(_Config) ->
+    %% sleepy_server does not implement handle_info/2
+    {ok, Pid} = wpool_process:start_link(?MODULE, crashy_server, {ok, state}, []),
+    Pid ! undef,
+    false = ktn_task:wait_for(fun() -> erlang:is_process_alive(Pid) end, false),
+    {comment, []}.
+
 -spec format_status(config()) -> {comment, []}.
 format_status(_Config) ->
     %% echo_server implements format_status/1
@@ -319,7 +334,7 @@ complete_coverage(_Config) ->
     ct:comment("Code Change"),
     {ok, State} = wpool_process:init({complete_coverage, echo_server, {ok, state}, []}),
     {ok, _} = wpool_process:code_change("oldvsn", State, {ok, state}),
-    {error, bad} = wpool_process:code_change("oldvsn", State, bad),
+    {error, bad} = wpool_process:code_change("oldvsn", State, {error, bad}),
 
     {comment, []}.