diff --git a/src/variant.cpp b/src/variant.cpp
index fa0427781a0..b96df59254f 100644
--- a/src/variant.cpp
+++ b/src/variant.cpp
@@ -345,7 +345,7 @@ const variant& variant::operator[](size_t n) const
 	return list_->elements[n];
 }
 
-const variant& variant::operator[](const variant v) const
+const variant& variant::operator[](const variant& v) const
 {
 	if(type_ == TYPE_CALLABLE) {
 		assert(v.as_int() == 0);
diff --git a/src/variant.hpp b/src/variant.hpp
index 0534b187bcb..8544a5bad4d 100644
--- a/src/variant.hpp
+++ b/src/variant.hpp
@@ -55,7 +55,7 @@ public:
 	const variant& operator=(const variant& v);
 
 	const variant& operator[](size_t n) const;
-	const variant& operator[](const variant v) const;
+	const variant& operator[](const variant& v) const;
 	size_t num_elements() const;
 	bool is_empty() const;