diff --git a/taglib/ape/apefooter.cpp b/taglib/ape/apefooter.cpp
index d54ddfe4..d18ac59b 100644
--- a/taglib/ape/apefooter.cpp
+++ b/taglib/ape/apefooter.cpp
@@ -28,6 +28,8 @@
 
 #include <bitset>
 
+#include "taglib.h"
+
 using namespace TagLib;
 using namespace APE;
 
diff --git a/taglib/ape/apetag.h b/taglib/ape/apetag.h
index f3a52805..804b130f 100644
--- a/taglib/ape/apetag.h
+++ b/taglib/ape/apetag.h
@@ -29,6 +29,7 @@
 #include "tbytevector.h"
 #include "tmap.h"
 #include "tstring.h"
+#include "taglib.h"
 #include "taglib_export.h"
 #include "tag.h"
 #include "apeitem.h"
diff --git a/taglib/mpeg/id3v1/id3v1tag.h b/taglib/mpeg/id3v1/id3v1tag.h
index e3fd4dd3..e85023ef 100644
--- a/taglib/mpeg/id3v1/id3v1tag.h
+++ b/taglib/mpeg/id3v1/id3v1tag.h
@@ -27,6 +27,7 @@
 #define TAGLIB_ID3V1TAG_H
 
 #include "tbytevector.h"
+#include "taglib.h"
 #include "taglib_export.h"
 #include "tag.h"
 
diff --git a/taglib/mpeg/id3v2/id3v2tag.h b/taglib/mpeg/id3v2/id3v2tag.h
index f99f6218..20fa0b7a 100644
--- a/taglib/mpeg/id3v2/id3v2tag.h
+++ b/taglib/mpeg/id3v2/id3v2tag.h
@@ -30,6 +30,7 @@
 #include "tstring.h"
 #include "tlist.h"
 #include "tmap.h"
+#include "taglib.h"
 #include "taglib_export.h"
 #include "tag.h"
 #include "id3v2.h"
diff --git a/taglib/ogg/oggpage.h b/taglib/ogg/oggpage.h
index 8c5e60aa..64ac01c9 100644
--- a/taglib/ogg/oggpage.h
+++ b/taglib/ogg/oggpage.h
@@ -27,6 +27,7 @@
 #define TAGLIB_OGGPAGE_H
 
 #include "tbytevectorlist.h"
+#include "taglib.h"
 #include "taglib_export.h"
 
 namespace TagLib {
diff --git a/taglib/ogg/oggpageheader.h b/taglib/ogg/oggpageheader.h
index ae45a2df..a17e4e5d 100644
--- a/taglib/ogg/oggpageheader.h
+++ b/taglib/ogg/oggpageheader.h
@@ -28,6 +28,7 @@
 
 #include "tlist.h"
 #include "tbytevector.h"
+#include "taglib.h"
 #include "taglib_export.h"
 
 namespace TagLib {
diff --git a/taglib/tagutils.h b/taglib/tagutils.h
index 4532a18c..e73d2c06 100644
--- a/taglib/tagutils.h
+++ b/taglib/tagutils.h
@@ -31,6 +31,7 @@
 #ifndef DO_NOT_DOCUMENT  // tell Doxygen not to document this header
 
 #include "tbytevector.h"
+#include "taglib.h"
 
 namespace TagLib {
 
diff --git a/taglib/toolkit/taglib.h b/taglib/toolkit/taglib.h
index 34bb394b..984cad3c 100644
--- a/taglib/toolkit/taglib.h
+++ b/taglib/toolkit/taglib.h
@@ -42,8 +42,6 @@
 #include <sys/types.h>
 #endif
 
-#include <string>
-
 //! A namespace for all TagLib related classes and functions
 
 /*!
@@ -58,15 +56,6 @@ namespace TagLib {
 
   class String;
 
-  // These integer types are deprecated. Do not use them.
-
-  using wchar = wchar_t; // Assumed to be sufficient to store a UTF-16 char.
-  using uchar = unsigned char;
-  using ushort = unsigned short;
-  using uint = unsigned int;
-  using ulong = unsigned long;
-  using ulonglong = unsigned long long;
-
   // Offset or length type for I/O streams.
   // In Win32, always 64bit. Otherwise, equivalent to off_t.
 #ifdef _WIN32
@@ -75,11 +64,6 @@ namespace TagLib {
   using offset_t = off_t;
 #endif
 
-  /*!
-   * Unfortunately \c std::wstring isn't defined on some systems, (i.e. GCC < 3)
-   * so I'm providing something here that should be constant.
-   */
-  using wstring = std::basic_string<wchar_t>;
 }  // namespace TagLib
 
 /*!
diff --git a/taglib/toolkit/tbytevector.h b/taglib/toolkit/tbytevector.h
index 668a24b3..abf88210 100644
--- a/taglib/toolkit/tbytevector.h
+++ b/taglib/toolkit/tbytevector.h
@@ -28,8 +28,8 @@
 
 #include <memory>
 #include <vector>
+#include <iosfwd>
 
-#include "taglib.h"
 #include "taglib_export.h"
 
 namespace TagLib {
diff --git a/taglib/toolkit/tdebuglistener.cpp b/taglib/toolkit/tdebuglistener.cpp
index 9a9bcd7c..745ede8e 100644
--- a/taglib/toolkit/tdebuglistener.cpp
+++ b/taglib/toolkit/tdebuglistener.cpp
@@ -42,7 +42,7 @@ namespace
     {
 #ifdef _WIN32
 
-      const wstring wstr = msg.toWString();
+      const std::wstring wstr = msg.toWString();
       const int len = WideCharToMultiByte(CP_ACP, 0, wstr.c_str(), -1, nullptr, 0, nullptr, nullptr);
       if(len != 0) {
         std::vector<char> buf(len);
diff --git a/taglib/toolkit/tiostream.h b/taglib/toolkit/tiostream.h
index 29609b34..5429f86e 100644
--- a/taglib/toolkit/tiostream.h
+++ b/taglib/toolkit/tiostream.h
@@ -30,6 +30,10 @@
 #include "taglib_export.h"
 #include "taglib.h"
 
+#ifdef _WIN32
+#include <string>
+#endif
+
 namespace TagLib {
 
 #ifdef _WIN32
diff --git a/taglib/toolkit/tstring.cpp b/taglib/toolkit/tstring.cpp
index 3158bd79..f19a6755 100644
--- a/taglib/toolkit/tstring.cpp
+++ b/taglib/toolkit/tstring.cpp
@@ -27,6 +27,7 @@
 
 #include <cerrno>
 #include <climits>
+#include <iostream>
 #include <utf8.h>
 
 #include "tdebug.h"
@@ -139,7 +140,7 @@ namespace TagLib {
     /*!
      * Stores string in UTF-16. The byte order depends on the CPU endian.
      */
-    TagLib::wstring data;
+    std::wstring data;
 
     /*!
      * This is only used to hold the most recent value of toCString().
@@ -170,19 +171,19 @@ String::String(const std::string &s, Type t) :
   }
 }
 
-String::String(const wstring &s) :
+String::String(const std::wstring &s) :
  String(s, wcharByteOrder())
 {
 }
 
-String::String(const wstring &s, Type t) :
+String::String(const std::wstring &s, Type t) :
   d(std::make_shared<StringPrivate>())
 {
   if(t == UTF16 || t == UTF16BE || t == UTF16LE) {
     copyFromUTF16(d->data, s.c_str(), s.length(), t);
   }
   else {
-    debug("String::String() -- TagLib::wstring should not contain Latin1 or UTF-8.");
+    debug("String::String() -- std::wstring should not contain Latin1 or UTF-8.");
   }
 }
 
@@ -263,7 +264,7 @@ std::string String::to8Bit(bool unicode) const
   return std::string(v.data(), v.size());
 }
 
-TagLib::wstring String::toWString() const
+std::wstring String::toWString() const
 {
   return d->data;
 }
@@ -618,7 +619,7 @@ String &String::operator=(const std::string &s)
   return *this;
 }
 
-String &String::operator=(const wstring &s)
+String &String::operator=(const std::wstring &s)
 {
   String(s).swap(*this);
   return *this;
diff --git a/taglib/toolkit/tstring.h b/taglib/toolkit/tstring.h
index 48f3d1bb..f7e40815 100644
--- a/taglib/toolkit/tstring.h
+++ b/taglib/toolkit/tstring.h
@@ -30,7 +30,6 @@
 
 #include "tbytevector.h"
 #include "taglib_export.h"
-#include "taglib.h"
 
 /*!
  * \relates TagLib::String
@@ -67,7 +66,7 @@ namespace TagLib {
 
   /*!
    * This is an implicitly shared \e wide string.  For storage it uses
-   * TagLib::wstring, but as this is an <i>implementation detail</i> this of
+   * std::wstring, but as this is an <i>implementation detail</i> this of
    * course could change.  Strings are stored internally as UTF-16 (without
    * BOM/CPU byte order)
    *
@@ -85,8 +84,8 @@ namespace TagLib {
   public:
 
 #ifndef DO_NOT_DOCUMENT
-    using Iterator = TagLib::wstring::iterator;
-    using ConstIterator = TagLib::wstring::const_iterator;
+    using Iterator = std::wstring::iterator;
+    using ConstIterator = std::wstring::const_iterator;
 #endif
 
     /**
@@ -141,12 +140,12 @@ namespace TagLib {
     /*!
      * Makes a deep copy of the data in \a s, which are in CPU byte order.
      */
-    String(const wstring &s);
+    String(const std::wstring &s);
 
     /*!
      * Makes a deep copy of the data in \a s, which are in byte order \a t.
      */
-    String(const wstring &s, Type t);
+    String(const std::wstring &s, Type t);
 
     /*!
      * Makes a deep copy of the data in \a s, which are in CPU byte order.
@@ -204,7 +203,7 @@ namespace TagLib {
      *
      * \see toCWString()
      */
-    wstring toWString() const;
+    std::wstring toWString() const;
 
     /*!
      * Creates and returns a standard C-style (null-terminated) version of this
@@ -470,7 +469,7 @@ namespace TagLib {
     /*!
      * Performs a deep copy of the data in \a s.
      */
-    String &operator=(const wstring &s);
+    String &operator=(const std::wstring &s);
 
     /*!
      * Performs a deep copy of the data in \a s.
diff --git a/taglib/toolkit/tstringlist.h b/taglib/toolkit/tstringlist.h
index 2c599797..a12cf3ab 100644
--- a/taglib/toolkit/tstringlist.h
+++ b/taglib/toolkit/tstringlist.h
@@ -26,8 +26,6 @@
 #ifndef TAGLIB_STRINGLIST_H
 #define TAGLIB_STRINGLIST_H
 
-#include <iostream>
-
 #include "tstring.h"
 #include "tlist.h"
 #include "tbytevectorlist.h"
diff --git a/taglib/toolkit/tvariant.h b/taglib/toolkit/tvariant.h
index 2d6c843c..a8408e54 100644
--- a/taglib/toolkit/tvariant.h
+++ b/taglib/toolkit/tvariant.h
@@ -26,6 +26,8 @@
 #ifndef TAGLIB_VARIANT_H
 #define TAGLIB_VARIANT_H
 
+#include <iosfwd>
+
 #include "tlist.h"
 #include "tmap.h"
 #include "taglib_export.h"