diff --git a/lib/base/initialize.cpp b/lib/base/initialize.cpp
index 23373cc23..e1dbec547 100644
--- a/lib/base/initialize.cpp
+++ b/lib/base/initialize.cpp
@@ -5,7 +5,7 @@
 
 using namespace icinga;
 
-bool icinga::InitializeOnceHelper(void (*func)(), int priority)
+bool icinga::InitializeOnceHelper(const std::function<void()>& func, int priority)
 {
 	Loader::AddDeferredInitializer(func, priority);
 	return true;
diff --git a/lib/base/initialize.hpp b/lib/base/initialize.hpp
index 0629abe68..446ad69af 100644
--- a/lib/base/initialize.hpp
+++ b/lib/base/initialize.hpp
@@ -4,6 +4,7 @@
 #define INITIALIZE_H
 
 #include "base/i2-base.hpp"
+#include <functional>
 
 namespace icinga
 {
@@ -13,7 +14,7 @@ namespace icinga
 
 #define I2_UNIQUE_NAME(prefix) I2_TOKENPASTE2(prefix, __COUNTER__)
 
-bool InitializeOnceHelper(void (*func)(), int priority = 0);
+bool InitializeOnceHelper(const std::function<void()>& func, int priority = 0);
 
 #define INITIALIZE_ONCE(func)									\
 	namespace { namespace I2_UNIQUE_NAME(io) {							\