diff --git a/include/rexy/string_base.hpp b/include/rexy/string_base.hpp
index bb2a9a4..6b044eb 100644
--- a/include/rexy/string_base.hpp
+++ b/include/rexy/string_base.hpp
@@ -94,7 +94,7 @@ namespace rexy{
 		constexpr string_intermediary(rexy::steal<char*> data)noexcept;
 		string_intermediary(const char* data, size_t len)noexcept(noexcept(Allocator::copy(data,len)));
 		string_intermediary(const char* data)noexcept(noexcept(Allocator::copy(data, m_cap)));
-		string_intermediary(size_t len)noexcept(noexcept(Allocator::allocate(len)));
+		explicit string_intermediary(size_t len)noexcept(noexcept(Allocator::allocate(len)));
 		string_intermediary(size_t len, size_t cap)noexcept(noexcept(Allocator::allocate(len)));
 
 		//normal copy and move ctors