diff --git a/VulkanHppGenerator.cpp b/VulkanHppGenerator.cpp
index 39b9da8..cca76f9 100644
--- a/VulkanHppGenerator.cpp
+++ b/VulkanHppGenerator.cpp
@@ -450,7 +450,7 @@ std::string const uniqueHandleHeader = { R"(
   class UniqueHandle
   {
   public:
-    UniqueHandle( Type const& value = Type(), Deleter const& deleter = Deleter() )
+    explicit UniqueHandle( Type const& value = Type(), Deleter const& deleter = Deleter() )
       : m_value( value )
       , m_deleter( deleter )
     {}
diff --git a/vulkan/vulkan.hpp b/vulkan/vulkan.hpp
index f0cfd9e..ab45590 100644
--- a/vulkan/vulkan.hpp
+++ b/vulkan/vulkan.hpp
@@ -333,7 +333,7 @@ namespace vk
   class UniqueHandle
   {
   public:
-    UniqueHandle( Type const& value = Type(), Deleter const& deleter = Deleter() )
+    explicit UniqueHandle( Type const& value = Type(), Deleter const& deleter = Deleter() )
       : m_value( value )
       , m_deleter( deleter )
     {}