1 files changed, 7 insertions, 0 deletions
diff --git a/src/libutil/ref.hh b/src/libutil/ref.hh
index 9f5da0915..85afa2811 100644
--- a/src/libutil/ref.hh
+++ b/src/libutil/ref.hh
@@ -28,6 +28,13 @@ public:
             throw std::invalid_argument("null pointer cast to ref");
     }
 
+    explicit ref<T>(T * p)
+        : p(p)
+    {
+        if (!p)
+            throw std::invalid_argument("null pointer cast to ref");
+    }
+
     T* operator ->() const
     {
         return &*p;