diff --git a/lib/config/configcompilercontext.cpp b/lib/config/configcompilercontext.cpp
index 1ebded614..380fc242d 100644
--- a/lib/config/configcompilercontext.cpp
+++ b/lib/config/configcompilercontext.cpp
@@ -27,16 +27,22 @@ using namespace icinga;
 
 void ConfigCompilerContext::AddMessage(bool error, const String& message)
 {
+	boost::mutex::scoped_lock lock(m_Mutex);
+
 	m_Messages.push_back(ConfigCompilerMessage(error, message));
 }
 
 std::vector<ConfigCompilerMessage> ConfigCompilerContext::GetMessages(void) const
 {
+	boost::mutex::scoped_lock lock(m_Mutex);
+
 	return m_Messages;
 }
 
 bool ConfigCompilerContext::HasErrors(void) const
 {
+	boost::mutex::scoped_lock lock(m_Mutex);
+
 	BOOST_FOREACH(const ConfigCompilerMessage& message, m_Messages) {
 		if (message.Error)
 			return true;
@@ -47,6 +53,8 @@ bool ConfigCompilerContext::HasErrors(void) const
 
 void ConfigCompilerContext::Reset(void)
 {
+	boost::mutex::scoped_lock lock(m_Mutex);
+
 	m_Messages.clear();
 }
 
diff --git a/lib/config/configcompilercontext.h b/lib/config/configcompilercontext.h
index 0194f7a79..a9f43b60f 100644
--- a/lib/config/configcompilercontext.h
+++ b/lib/config/configcompilercontext.h
@@ -53,6 +53,8 @@ public:
 
 private:
         std::vector<ConfigCompilerMessage> m_Messages;
+
+	mutable boost::mutex m_Mutex;
 };
 
 }