diff --git a/src/OpenMesh/Core/Mesh/ArrayKernel.hh b/src/OpenMesh/Core/Mesh/ArrayKernel.hh
index 56398b70..b9c97fa1 100644
--- a/src/OpenMesh/Core/Mesh/ArrayKernel.hh
+++ b/src/OpenMesh/Core/Mesh/ArrayKernel.hh
@@ -738,7 +738,7 @@ public:
     typedef typename HandleContainer::const_iterator
                                             const_iterator;
   public:
-    ExtStatusSetT(ArrayKernel& _kernel, size_t _capacity_hint = 0)
+    explicit ExtStatusSetT(ArrayKernel& _kernel, size_t _capacity_hint = 0)
     : Base(_kernel)
     { handles_.reserve(_capacity_hint); }