diff --git a/base/stream.jl b/base/stream.jl
index 5799fe4458537..f58ab568437af 100644
--- a/base/stream.jl
+++ b/base/stream.jl
@@ -771,12 +771,13 @@ function write(s::AsyncStream, b::UInt8)
     return 1
 end
 function write(s::AsyncStream, c::Char)
-    @uv_write utf8sizeof(c) ccall(:jl_pututf8_copy, Int32, (Ptr{Void},UInt32, Ptr{Void}, Ptr{Void}), handle(s), c, uvw, uv_jl_writecb_task::Ptr{Void})
+    nb = utf8sizeof(c)
+    @uv_write nb ccall(:jl_pututf8_copy, Int32, (Ptr{Void}, UInt32, Ptr{Void}, Ptr{Void}), handle(s), c, uvw, uv_jl_writecb_task::Ptr{Void})
     ct = current_task()
     uv_req_set_data(uvw,ct)
     ct.state = :waiting
     stream_wait(ct)
-    return utf8sizeof(c)
+    return nb
 end
 function write{T}(s::AsyncStream, a::Array{T})
     if isbits(T)
diff --git a/base/string.jl b/base/string.jl
index 86c9e3fd0f6f2..71231e0951c7e 100644
--- a/base/string.jl
+++ b/base/string.jl
@@ -587,7 +587,8 @@ write{T<:ByteString}(to::IOBuffer, s::SubString{T}) =
     s.endof==0 ? 0 : write_sub(to, s.string.data, s.offset+1, next(s,s.endof)[2]-1)
 print(io::IOBuffer, s::SubString) = write(io, s)
 
-sizeof{T<:ByteString}(s::SubString{T}) = s.endof==0 ? 0 : next(s,s.endof)[2]-1
+sizeof(s::SubString{ASCIIString}) = s.endof
+sizeof(s::SubString{UTF8String}) = s.endof == 0 ? 0 : next(s,s.endof)[2]-1
 
 # TODO: length(s::SubString) = ??
 # default implementation will work but it's slow