diff --git a/lib/base/debug.h b/lib/base/debug.h
index bc785f43a..98050f3f4 100644
--- a/lib/base/debug.h
+++ b/lib/base/debug.h
@@ -20,8 +20,7 @@
 #ifndef DEBUG_H
 #define DEBUG_H
 
-#include <stdlib.h>
-#include <stdio.h>
+#include "i2-base.h"
 
 #ifdef NDEBUG
 #	define ASSERT(expr) ((void)0)
diff --git a/lib/base/utility.cpp b/lib/base/utility.cpp
index 602521b07..698f378d6 100644
--- a/lib/base/utility.cpp
+++ b/lib/base/utility.cpp
@@ -586,3 +586,11 @@ int Utility::CompareVersion(const String& v1, const String& v2)
 
 	return 0;
 }
+
+int Utility::Random(void)
+{
+	static boost::mutex mtx;
+	boost::mutex::scoped_lock lock(mtx);
+
+	return rand();
+}
diff --git a/lib/base/utility.h b/lib/base/utility.h
index 5a5bdb9d8..8c9d587af 100644
--- a/lib/base/utility.h
+++ b/lib/base/utility.h
@@ -99,6 +99,8 @@ public:
 
 	static int CompareVersion(const String& v1, const String& v2);
 
+	static int Random(void);
+
 private:
 	Utility(void);
 
diff --git a/lib/icinga/nullchecktask.cpp b/lib/icinga/nullchecktask.cpp
index 9fc0bb1f1..371600309 100644
--- a/lib/icinga/nullchecktask.cpp
+++ b/lib/icinga/nullchecktask.cpp
@@ -40,30 +40,10 @@ Dictionary::Ptr NullCheckTask::ScriptFunc(const Service::Ptr&)
 	String output = "Hello from ";
 	output += name;
 
-#ifndef _WIN32
-	unsigned int seed = Utility::GetPid() * time(NULL);
-	int state = rand_r(&seed) % 4;
-#else
-	int state = 0;
-#endif
-
 	Dictionary::Ptr cr = boost::make_shared<Dictionary>();
 	cr->Set("output", output);
-	cr->Set("state", ExitStatusToState(state));
+	cr->Set("state", static_cast<ServiceState>(Utility::Random() % 4));
 
 	return cr;
 }
 
-ServiceState NullCheckTask::ExitStatusToState(int exitStatus)
-{
-	switch (exitStatus) {
-		case 0:
-			return StateOK;
-		case 1:
-			return StateWarning;
-		case 2:
-			return StateCritical;
-		default:
-			return StateUnknown;
-	}
-}
diff --git a/lib/icinga/nullchecktask.h b/lib/icinga/nullchecktask.h
index edd8a1ade..fa9fcf873 100644
--- a/lib/icinga/nullchecktask.h
+++ b/lib/icinga/nullchecktask.h
@@ -36,7 +36,6 @@ class I2_ICINGA_API NullCheckTask
 {
 public:
 	static Dictionary::Ptr ScriptFunc(const Service::Ptr& service);
-        static ServiceState ExitStatusToState(int exitStatus);
 
 private:
 	NullCheckTask(void);
diff --git a/lib/icinga/service.cpp b/lib/icinga/service.cpp
index 465befd99..52bba4cfb 100644
--- a/lib/icinga/service.cpp
+++ b/lib/icinga/service.cpp
@@ -48,7 +48,7 @@ void Service::Start(void)
 
 	VERIFY(GetHost());
 
-	SetSchedulingOffset(rand());
+	SetSchedulingOffset(Utility::Random());
 	UpdateNextCheck();
 
 	AddDowntimesToCache();