diff --git a/src/Functions/visibleWidth.cpp b/src/Functions/visibleWidth.cpp
index be9987890310..9a3edd9fbec6 100644
--- a/src/Functions/visibleWidth.cpp
+++ b/src/Functions/visibleWidth.cpp
@@ -33,7 +33,7 @@ class FunctionVisibleWidth : public IFunction
         return std::make_shared<FunctionVisibleWidth>(context);
     }
 
-    FunctionVisibleWidth(ContextPtr context)
+    explicit FunctionVisibleWidth(ContextPtr context)
     {
         behavior = context->getSettingsRef().function_visible_width_behavior;
     }