diff --git a/api/Makefile.am b/api/Makefile.am
index 2cb933b35392e0d3f0ca76472f1e0ec383efab64..05cc8b3e751b38d69beaaca70e0a4a1b65415348 100644
--- a/api/Makefile.am
+++ b/api/Makefile.am
@@ -73,14 +73,16 @@ tesseract_CPPFLAGS += -DTESS_IMPORTS
 endif
 
 tesseract_LDADD = libtesseract.la
-if !OSX
-tesseract_LDADD += -lrt
-endif
+
 if USE_OPENCL
 tesseract_LDADD += $(OPENCL_LIB)
 endif
+
 if MINGW
 tesseract_LDADD += -lws2_32
-libtesseract_la_LDFLAGS += -no-undefined  -Wl,--as-needed -lws2_32
+libtesseract_la_LDFLAGS += -no-undefined -Wl,--as-needed -lws2_32
+endif
+if ADD_RT
+tesseract_LDADD += -lrt
 endif
 
diff --git a/api/baseapi.cpp b/api/baseapi.cpp
index 1861b0ef45699aa08b856560ca72b6ddb6a273e1..a6f22a49bac03b32034c612553c43bacb3bab4bf 100644
--- a/api/baseapi.cpp
+++ b/api/baseapi.cpp
@@ -26,6 +26,25 @@
 #include <signal.h>
 #endif
 
+#if defined(_WIN32)
+#ifdef _MSC_VER
+#include "mathfix.h"
+#elif MINGW
+// workaround for stdlib.h with -std=c++11 for _splitpath and _MAX_FNAME
+#undef __STRICT_ANSI__ 
+#endif // _MSC_VER
+#include <stdlib.h>
+#include <windows.h>
+#else
+#include <dirent.h>
+#include <libgen.h>
+#include <string.h>
+#endif // _WIN32
+
+#if !defined(VERSION)
+#include "version.h"
+#endif
+
 #include "allheaders.h"
 
 #include "baseapi.h"
@@ -54,22 +73,6 @@
 #include "strngs.h"
 #include "openclwrapper.h"
 
-#ifdef _WIN32
-#include <windows.h>
-#include <stdlib.h>
-#ifdef _MSC_VER
-#include "mathfix.h"
-#endif // _MSC_VER
-#else
-#include <dirent.h>
-#include <libgen.h>
-#include <string.h>
-#endif // _WIN32
-
-#if !defined(VERSION)
-#include "version.h"
-#endif
-
 namespace tesseract {
 
 /** Minimum sensible image size to be worth running tesseract. */
@@ -370,7 +373,7 @@ void TessBaseAPI::GetAvailableLanguagesAsVector(
       }
       FindClose(handle);
     }
-#else
+#else  // _WIN32
     DIR *dir;
     struct dirent *dirent;
     char *dot;
diff --git a/ccmain/pagesegmain.cpp b/ccmain/pagesegmain.cpp
index b960a211c56eb0e9b0c5fea9850b087e30359cd3..0d5de3dbc81277a8cb6b2950ba5f733dedb282d1 100644
--- a/ccmain/pagesegmain.cpp
+++ b/ccmain/pagesegmain.cpp
@@ -20,10 +20,13 @@
 #ifdef _WIN32
 #ifndef __GNUC__
 #include <windows.h>
-#endif  /* __GNUC__ */
+#endif  // __GNUC__
+#ifndef unlink
+#include <io.h>
+#endif
 #else
 #include <unistd.h>
-#endif
+#endif // _WIN32
 #ifdef _MSC_VER
 #pragma warning(disable:4244)  // Conversion warnings
 #endif
diff --git a/ccstruct/pdblock.cpp b/ccstruct/pdblock.cpp
index 643045321a024ce62022784d3abb2e50c4e1f39d..97365b53e7164304d73967711ece4bc5a8cc21c5 100644
--- a/ccstruct/pdblock.cpp
+++ b/ccstruct/pdblock.cpp
@@ -195,7 +195,7 @@ void PDBLK::plot(                //draw outline
     //              tprintf("Block %d bottom left is (%d,%d)\n",
     //                      serial,startpt.x(),startpt.y());
     char temp_buff[34];
-    #ifdef __UNIX__
+    #if defined(__UNIX__) || defined(MINGW)
     sprintf(temp_buff, INT32FORMAT, serial);
     #else
     ultoa (serial, temp_buff, 10);
diff --git a/ccstruct/polyblk.cpp b/ccstruct/polyblk.cpp
index d0c610f25fe01b33b5f54b7ea3b8ebd4b89faf8a..1583788596915ffa940166060953ced60f81574c 100644
--- a/ccstruct/polyblk.cpp
+++ b/ccstruct/polyblk.cpp
@@ -252,7 +252,7 @@ void POLY_BLOCK::plot(ScrollView* window, inT32 num) {
   if (num > 0) {
     window->TextAttributes("Times", 80, false, false, false);
     char temp_buff[34];
-    #ifdef __UNIX__
+    #if defined(__UNIX__) || defined(MINGW)
     sprintf(temp_buff, INT32FORMAT, num);
     #else
     ltoa (num, temp_buff, 10);
diff --git a/configure.ac b/configure.ac
index a8c1fe0aeda29fe2fc3d923db0a222304ccd11f0..e240682dd65fd546158d96aa18e4525da3926a35 100644
--- a/configure.ac
+++ b/configure.ac
@@ -8,7 +8,7 @@
 
 AC_PREREQ(2.50)
 AC_INIT([tesseract], [3.03], [http://code.google.com/p/tesseract-ocr/issues/list])
-CXXFLAGS=""
+CXXFLAGS=${CXXFLAGS:-""}
 AC_CONFIG_MACRO_DIR([m4])
 AC_REVISION([$Revision$])
 AC_CONFIG_AUX_DIR(config)
@@ -78,21 +78,24 @@ case "${host_os}" in
     mingw32*)
         AC_DEFINE_UNQUOTED(MINGW,1,[This is a MinGW system])
         AM_CONDITIONAL(MINGW, true)
+		AM_CONDITIONAL(ADD_RT, false)
         AC_SUBST([AM_LDFLAGS], ['-Wl,-no-undefined -Wl,--as-needed'])
         ;;
     solaris*)
         LIBS="-lsocket -lnsl -lrt -lxnet"
+		AM_CONDITIONAL(ADD_RT, true)
         ;;
     *-*-darwin*)
         OPENCL_LIBS="-framework OpenCL"
         OPENCL_INC=""
-        AM_CONDITIONAL(OSX, true)
+        AM_CONDITIONAL(ADD_RT, false)
         ;;
     powerpc-*-darwin*)
         OPENCL_LIBS=""
         ;;
-     *)
+    *)
         # default
+		AM_CONDITIONAL(ADD_RT, true)
         ;;
 esac
 
diff --git a/opencl/openclwrapper.cpp b/opencl/openclwrapper.cpp
index 9f02c353d23b015c956060b238318d57d2837c15..ac1812e39bdf1ed39048805f5c51a1c78baa733f 100644
--- a/opencl/openclwrapper.cpp
+++ b/opencl/openclwrapper.cpp
@@ -1,4 +1,4 @@
-#ifdef WIN32
+#ifdef _WIN32
 #include <Windows.h>
 #include <io.h>
 #else