diff --git a/reactos/tools/rbuild/XML.cpp b/reactos/tools/rbuild/XML.cpp
index a689fbf96b0..f5f9758af7a 100644
--- a/reactos/tools/rbuild/XML.cpp
+++ b/reactos/tools/rbuild/XML.cpp
@@ -2,8 +2,13 @@
 
 #include "pch.h"
 
+#ifdef WIN32
 #include <direct.h>
 #include <io.h>
+#else
+#include <sys/stat.h>
+#define _MAX_PATH 255
+#endif
 #include <assert.h>
 
 #include "XML.h"
@@ -63,7 +68,7 @@ filelen ( FILE* f )
 {
 #ifdef WIN32
 	return _filelengthi64 ( _fileno(f) );
-#elif defined(UNIX)
+#else
 	struct stat64 file_stat;
 	if ( fstat64(fileno(f), &file_stat) != 0 )
 		return 0;
diff --git a/reactos/tools/rbuild/backend/backend.cpp b/reactos/tools/rbuild/backend/backend.cpp
index 02da1dcf030..f6081e28140 100644
--- a/reactos/tools/rbuild/backend/backend.cpp
+++ b/reactos/tools/rbuild/backend/backend.cpp
@@ -1,7 +1,7 @@
 
 #include "../pch.h"
 
-#include "../Rbuild.h"
+#include "../rbuild.h"
 #include "backend.h"
 
 using std::string;
diff --git a/reactos/tools/rbuild/pch.h b/reactos/tools/rbuild/pch.h
index c0881b7a3fb..0cda23145b0 100644
--- a/reactos/tools/rbuild/pch.h
+++ b/reactos/tools/rbuild/pch.h
@@ -13,4 +13,20 @@
 
 #include <stdarg.h>
 
+#ifndef WIN32
+#include <wctype.h>
+#include <math.h>
+
+inline char* strlwr ( char* str )
+{
+  char* p = str;
+  while ( *p )
+    *p++ = tolower(*p);
+  return str;
+}
+
+#define _finite __finite
+#define _isnan __isnan
+#endif
+
 #endif//PCH_H
diff --git a/reactos/tools/rbuild/rbuild.cpp b/reactos/tools/rbuild/rbuild.cpp
index d0e24bf920e..563bc2d04d7 100644
--- a/reactos/tools/rbuild/rbuild.cpp
+++ b/reactos/tools/rbuild/rbuild.cpp
@@ -4,7 +4,9 @@
 #include <typeinfo>
 
 #include <stdio.h>
+#ifdef WIN32
 #include <io.h>
+#endif
 #include <assert.h>
 
 #include "rbuild.h"
diff --git a/reactos/tools/rbuild/ssprintf.cpp b/reactos/tools/rbuild/ssprintf.cpp
index dbd2bc2a34a..d8c415fc965 100644
--- a/reactos/tools/rbuild/ssprintf.cpp
+++ b/reactos/tools/rbuild/ssprintf.cpp
@@ -1,5 +1,7 @@
 // ssprintf.cpp
 
+#include "pch.h"
+
 #include <malloc.h>
 #include <math.h>
 #include <float.h>
@@ -10,8 +12,13 @@
 #define alloca _alloca
 #endif//_MSC_VER
 
+#ifdef _MSC_VER
 typedef __int64 LONGLONG;
 typedef unsigned __int64 ULONGLONG;
+#else
+typedef long long LONGLONG;
+typedef unsigned long long ULONGLONG;
+#endif
 
 typedef struct {
     unsigned int mantissa:23;