diff --git a/src/StdLib.jl b/src/StdLib.jl
index 320f2e4..5eb4199 100644
--- a/src/StdLib.jl
+++ b/src/StdLib.jl
@@ -112,9 +112,9 @@ Base.cmp(a::String, b::CppBasicString) = cmp(a,String(b))
 
 # Make sure functions taking a C++ string as argument can also take a Julia string
 CxxWrapCore.map_julia_arg_type(x::Type{<:StdString}) = AbstractString
-StdLib.StdStringAllocated(x::String) = StdString(x)
-Base.cconvert(::Type{CxxWrapCore.ConstCxxRef{StdString}}, x::String) = StdString(x)
-Base.cconvert(::Type{StdLib.StdStringDereferenced}, x::String) = StdString(x)
+StdLib.StdStringAllocated(x::String) = StdString(x,length(x))
+Base.cconvert(::Type{CxxWrapCore.ConstCxxRef{StdString}}, x::String) = StdString(x,length(x))
+Base.cconvert(::Type{StdLib.StdStringDereferenced}, x::String) = StdString(x,length(x))
 Base.unsafe_convert(::Type{CxxWrapCore.ConstCxxRef{StdString}}, x::StdString) = ConstCxxRef(x)
 
 function StdValArray(v::Vector{T}) where {T}