diff --git a/event.go b/event.go
index 0c2e1ad..4b80311 100644
--- a/event.go
+++ b/event.go
@@ -26,7 +26,7 @@ type eventData struct {
 // mutated or holds references to mutable data.
 //
 // RPC exported method
-func (s PluginServer) HandleEvent(in StartEventData, out *StepData) error {
+func (s *PluginServer) HandleEvent(in StartEventData, out *StepData) error {
 	s.lock.RLock()
 	instance, ok := s.instances[in.InstanceId]
 	s.lock.RUnlock()
@@ -80,7 +80,7 @@ type StepData struct {
 // the return value is either a new callback request or a finish signal.
 //
 // RPC exported method
-func (s PluginServer) Step(in StepData, out *StepData) error {
+func (s *PluginServer) Step(in StepData, out *StepData) error {
 	s.lock.RLock()
 	event, ok := s.events[in.EventId]
 	s.lock.RUnlock()
diff --git a/instance.go b/instance.go
index e283f0a..948553a 100644
--- a/instance.go
+++ b/instance.go
@@ -93,7 +93,7 @@ func (s *PluginServer) StartInstance(config PluginConfig, status *InstanceStatus
 // InstanceStatus returns a given resource's status (the same given when started)
 //
 // RPC exported method
-func (s PluginServer) InstanceStatus(id int, status *InstanceStatus) error {
+func (s *PluginServer) InstanceStatus(id int, status *InstanceStatus) error {
 	s.lock.RLock()
 	instance, ok := s.instances[id]
 	s.lock.RUnlock()
@@ -117,7 +117,7 @@ func (s PluginServer) InstanceStatus(id int, status *InstanceStatus) error {
 // Returns the status just before closing.
 //
 // RPC exported method
-func (s PluginServer) CloseInstance(id int, status *InstanceStatus) error {
+func (s *PluginServer) CloseInstance(id int, status *InstanceStatus) error {
 	s.lock.RLock()
 	instance, ok := s.instances[id]
 	s.lock.RUnlock()
diff --git a/pluginserver.go b/pluginserver.go
index 0419a96..cb51d3c 100644
--- a/pluginserver.go
+++ b/pluginserver.go
@@ -45,17 +45,17 @@ func (s *PluginServer) SetPluginDir(dir string, reply *string) error {
 // --- pluginData  --- //
 
 type pluginData struct {
+	lock        sync.Mutex
 	name        string
 	code        *plugin.Plugin
 	constructor func() interface{}
 	config      interface{}
 }
 
-func (s PluginServer) loadPlugin(name string) (plug *pluginData, err error) {
-	s.lock.Lock()
-	defer s.lock.Unlock()
-
+func (s *PluginServer) loadPlugin(name string) (plug *pluginData, err error) {
+	s.lock.RLock()
 	plug, ok := s.plugins[name]
+	s.lock.RUnlock()
 	if ok {
 		return
 	}
@@ -85,7 +85,9 @@ func (s PluginServer) loadPlugin(name string) (plug *pluginData, err error) {
 		config:      constructor(),
 	}
 
+	s.lock.Lock()
 	s.plugins[name] = plug
+	s.lock.Unlock()
 
 	return
 }
@@ -166,6 +168,7 @@ func (s PluginServer) GetPluginInfo(name string, info *PluginInfo) error {
 
 	*info = PluginInfo{Name: name}
 
+	plug.lock.Lock()
 	handlers := getHandlers(plug.config)
 
 	info.Phases = make([]string, len(handlers))
@@ -194,6 +197,7 @@ func (s PluginServer) GetPluginInfo(name string, info *PluginInfo) error {
 	out.WriteString(st)
 
 	out.WriteString(`}}]}`)
+	plug.lock.Unlock()
 
 	info.Schema = out.String()