diff --git a/libtorrent/include/libtorrent/assert.hpp b/libtorrent/include/libtorrent/assert.hpp
index 71a1aa406..0000b6d53 100644
--- a/libtorrent/include/libtorrent/assert.hpp
+++ b/libtorrent/include/libtorrent/assert.hpp
@@ -33,6 +33,11 @@ POSSIBILITY OF SUCH DAMAGE.
 #ifndef TORRENT_ASSERT
 
 #include "libtorrent/config.hpp"
+
+#if !defined TORRENT_DEBUG
+#define TORRENT_ASSERT(a) do {} while(false)
+#else
+
 #include <string>
 
 #ifdef __GNUC__
@@ -51,3 +56,5 @@ TORRENT_EXPORT void assert_fail(const char* expr, int line, char const* file, ch
 
 #endif
 
+#endif
+
diff --git a/libtorrent/include/libtorrent/lazy_entry.hpp b/libtorrent/include/libtorrent/lazy_entry.hpp
index 547900c99..01d1ac3ca 100644
--- a/libtorrent/include/libtorrent/lazy_entry.hpp
+++ b/libtorrent/include/libtorrent/lazy_entry.hpp
@@ -38,6 +38,7 @@ POSSIBILITY OF SUCH DAMAGE.
 #include "libtorrent/assert.hpp"
 #include "libtorrent/size_type.hpp"
 #include <iosfwd>
+#include <string>
 
 namespace libtorrent
 {
diff --git a/libtorrent/src/gzip.cpp b/libtorrent/src/gzip.cpp
index 929816240..cf0c5b196 100644
--- a/libtorrent/src/gzip.cpp
+++ b/libtorrent/src/gzip.cpp
@@ -35,6 +35,7 @@ POSSIBILITY OF SUCH DAMAGE.
 #include "zlib.h"
 
 #include <vector>
+#include <string>
 
 namespace
 {