diff --git a/lib/icinga/checkable-dependency.cpp b/lib/icinga/checkable-dependency.cpp
index 736553a48..80f567356 100644
--- a/lib/icinga/checkable-dependency.cpp
+++ b/lib/icinga/checkable-dependency.cpp
@@ -3,6 +3,7 @@
 #include "icinga/service.hpp"
 #include "icinga/dependency.hpp"
 #include "base/logger.hpp"
+#include <unordered_map>
 
 using namespace icinga;