diff --git a/deps/build.jl b/deps/build.jl
index e75a4fb..3e8f08d 100644
--- a/deps/build.jl
+++ b/deps/build.jl
@@ -18,7 +18,7 @@ provides(Yum, "libpq5", libpq)
 provides(Yum, "postgresql-libs", libpq)
 provides(Pacman, "postgresql-libs", libpq)
 
-@osx_only begin
+@static if is_apple()
     using Homebrew
     provides(Homebrew.HB, "postgresql", libpq, os=:Darwin)
 end
diff --git a/src/dbi_impl.jl b/src/dbi_impl.jl
index 6c68149..47f09a1 100644
--- a/src/dbi_impl.jl
+++ b/src/dbi_impl.jl
@@ -89,16 +89,15 @@ function checkerrclear(result::Ptr{PGresult})
 end
 
 escapeliteral(db::PostgresDatabaseHandle, value) = value
-escapeliteral(db::PostgresDatabaseHandle, value::AbstractString) = escapeliteral(db, bytestring(value))
 
-function escapeliteral(db::PostgresDatabaseHandle, value::Union{ASCIIString, UTF8String})
+function escapeliteral(db::PostgresDatabaseHandle, value::String)
     strptr = PQescapeLiteral(db.ptr, value, sizeof(value))
     str = bytestring(strptr)
     PQfreemem(strptr)
     return str
 end
 
-function escapeidentifier(db::PostgresDatabaseHandle, value::Union{ASCIIString, UTF8String})
+function escapeidentifier(db::PostgresDatabaseHandle, value::String)
     strptr = PQescapeIdentifier(db.ptr, value, sizeof(value))
     str = bytestring(strptr)
     PQfreemem(strptr)
@@ -115,8 +114,7 @@ function checkcopyreturnval(db::PostgresDatabaseHandle, returnval::Int32)
     end
 end
 
-function copy_from(db::PostgresDatabaseHandle, table::AbstractString,
-                   filename::AbstractString, format::AbstractString)
+function copy_from(db::PostgresDatabaseHandle, table::AbstractString, filename::AbstractString, format::AbstractString)
     f = open(filename)
     try
         Base.run(db, string("COPY ", escapeidentifier(db, table), " FROM STDIN ", format))
@@ -138,7 +136,7 @@ function getparamtypes(result::Ptr{PGresult})
     return @compat [pgtype(OID{Int(PQparamtype(result, i-1))}) for i = 1:nparams]
 end
 
-LIBC = @windows ? "msvcrt.dll" : :libc
+LIBC = @static is_windows() ? "msvcrt.dll" : :libc
 strlen(ptr::Ptr{UInt8}) = ccall((:strlen, LIBC), Csize_t, (Ptr{UInt8},), ptr)
 
 function getparams!(ptrs::Vector{Ptr{UInt8}}, params, types, sizes, lengths::Vector{Int32}, nulls)
@@ -293,7 +291,7 @@ end
 function DBI.fetchdf(result::PostgresResultHandle)
     df = DataFrame()
     for i = 0:(length(result.types)-1)
-        df[symbol(bytestring(PQfname(result.ptr, i)))] = unsafe_fetchcol_dataarray(result, i)
+        df[Symbol(bytestring(PQfname(result.ptr, i)))] = unsafe_fetchcol_dataarray(result, i)
     end
 
     return df
diff --git a/src/libpq_common.jl b/src/libpq_common.jl
index 117808b..02fe849 100644
--- a/src/libpq_common.jl
+++ b/src/libpq_common.jl
@@ -1,5 +1,5 @@
 macro c(ret_type, func, arg_types, lib)
-    local args_in = Any[ symbol(string('a',x)) for x in 1:length(arg_types.args) ]
+    local args_in = Any[ Symbol(string('a',x)) for x in 1:length(arg_types.args) ]
     quote
         $(esc(func))($(args_in...)) = ccall( ($(string(func)), $(Expr(:quote, lib)) ),
                                             $ret_type, $arg_types, $(args_in...) )
diff --git a/src/types.jl b/src/types.jl
index 599d396..7d4f0f3 100644
--- a/src/types.jl
+++ b/src/types.jl
@@ -33,7 +33,7 @@ newpgtype(:int2, 21, (Int16,))
 newpgtype(:float8, 701, (Float64,))
 newpgtype(:float4, 700, (Float32,))
 newpgtype(:bpchar, 1042, ())
-newpgtype(:varchar, 1043, (ASCIIString,UTF8String))
+newpgtype(:varchar, 1043, (String,String))
 newpgtype(:text, 25, ())
 newpgtype(:numeric, 1700, (BigInt,BigFloat))
 newpgtype(:date, 1082, ())
@@ -50,8 +50,8 @@ newpgtype(:_int4, 1007, (Vector{Int32},))
 newpgtype(:_int2, 1005, (Vector{Int16},))
 newpgtype(:_float8, 1022, (Vector{Float64},))
 newpgtype(:_float4, 1021, (Vector{Float32},))
-newpgtype(:_varchar, 1015, (Vector{ASCIIString}, Vector{UTF8String}))
-newpgtype(:_text, 1009, (Vector{ASCIIString}, Vector{UTF8String}))
+newpgtype(:_varchar, 1015, (Vector{String}, Vector{String}))
+newpgtype(:_text, 1009, (Vector{String}, Vector{String}))
 
 
 typealias PGStringTypes Union{Type{PostgresType{:bpchar}},
@@ -151,10 +151,6 @@ function pgdata(::Type{PostgresType{:numeric}}, ptr::Ptr{UInt8}, data::Number)
     ptr = storestring!(ptr, string(data))
 end
 
-function pgdata(::PGStringTypes, ptr::Ptr{UInt8}, data::ByteString)
-    ptr = storestring!(ptr, data)
-end
-
 function pgdata(::PGStringTypes, ptr::Ptr{UInt8}, data::AbstractString)
     ptr = storestring!(ptr, bytestring(data))
 end
@@ -212,19 +208,11 @@ function pgdata(::Type{PostgresType{:_float4}}, ptr::Ptr{UInt8}, data::Vector{Fl
     ptr = storestring!(ptr, string("{", join(data, ','), "}"))
 end
 
-function pgdata(::Type{PostgresType{:_varchar}}, ptr::Ptr{UInt8}, data::Vector{ASCIIString})
-    ptr = storestring!(ptr, string("{", join(data, ','), "}"))
-end
-
-function pgdata(::Type{PostgresType{:_varchar}}, ptr::Ptr{UInt8}, data::Vector{UTF8String})
-    ptr = storestring!(ptr, string("{", join(data, ','), "}"))
-end
-
-function pgdata(::Type{PostgresType{:_text}}, ptr::Ptr{UInt8}, data::Vector{ASCIIString})
+function pgdata(::Type{PostgresType{:_varchar}}, ptr::Ptr{UInt8}, data::Vector{String})
     ptr = storestring!(ptr, string("{", join(data, ','), "}"))
 end
 
-function pgdata(::Type{PostgresType{:_text}}, ptr::Ptr{UInt8}, data::Vector{UTF8String})
+function pgdata(::Type{PostgresType{:_text}}, ptr::Ptr{UInt8}, data::Vector{String})
     ptr = storestring!(ptr, string("{", join(data, ','), "}"))
 end
 
diff --git a/test/connection.jl b/test/connection.jl
index 89e8162..74dd9d3 100644
--- a/test/connection.jl
+++ b/test/connection.jl
@@ -8,9 +8,9 @@ function test_connection()
     @test conn.status == PostgreSQL.CONNECTION_OK
     @test errcode(conn) == PostgreSQL.CONNECTION_OK
     @test !conn.closed
-    @test bytestring(libpq.PQdb(conn.ptr)) == "julia_test"
-    @test bytestring(libpq.PQuser(conn.ptr)) == "postgres"
-    @test bytestring(libpq.PQport(conn.ptr)) == "5432"
+    @test unsafe_string(libpq.PQdb(conn.ptr)) == "julia_test"
+    @test unsafe_string(libpq.PQuser(conn.ptr)) == "postgres"
+    @test unsafe_string(libpq.PQport(conn.ptr)) == "5432"
 
     disconnect(conn)
     @test conn.closed
@@ -33,9 +33,9 @@ function test_connection()
     @test conn.status == PostgreSQL.CONNECTION_OK
     @test errcode(conn) == PostgreSQL.CONNECTION_OK
     @test !conn.closed
-    @test bytestring(libpq.PQdb(conn.ptr)) == "julia_test"
-    @test bytestring(libpq.PQuser(conn.ptr)) == "postgres"
-    @test bytestring(libpq.PQport(conn.ptr)) == "5432"
+    @test unsafe_string(libpq.PQdb(conn.ptr)) == "julia_test"
+    @test unsafe_string(libpq.PQuser(conn.ptr)) == "postgres"
+    @test unsafe_string(libpq.PQport(conn.ptr)) == "5432"
 
     disconnect(conn)
     @test conn.closed