diff --git a/core/build/make-svn-rev-header.py b/core/build/make-svn-rev-header.py
index 705382f8b..7876d9ff4 100644
--- a/core/build/make-svn-rev-header.py
+++ b/core/build/make-svn-rev-header.py
@@ -11,19 +11,27 @@
 
 from xml.dom.minidom import parse
 from time import gmtime, strftime
+from os.path import isfile
+from sys import exit
 
 entries_file = parse('../.svn/entries')
 
 def getRevision(entries):
-	for entry in entries:
-		if entry.getAttribute("name") == "":
-			return entry.getAttribute("revision")
+    for entry in entries:
+        if entry.getAttribute("name") == "":
+            return entry.getAttribute("revision")
 
 revision = getRevision(entries_file.getElementsByTagName("entry"))
 
+if isfile("svn-revision.h"):
+    infile = file("svn-revision.h", "r")
+    for ln in infile:
+        if ln == "#define BUILD_SVN_REVISION " + revision + "\n":
+            infile.close()
+            exit()
+
 outfile = file("svn-revision.h", "w+")
 outfile.write("// This file is automatically generated by make-svn-rev-header.py\n")
 outfile.write("// Do not modify or add to revision control\n\n")
 outfile.write("#define BUILD_SVN_REVISION " + revision + "\n")
-outfile.write("#define BUILD_TIMESTAMP \"" + strftime("%a, %d %b %Y %H:%M:%S +0000", gmtime()) + "\"\n")
 outfile.close()
diff --git a/core/version.cpp b/core/version.cpp
index 026132f94..5789762f7 100644
--- a/core/version.cpp
+++ b/core/version.cpp
@@ -49,13 +49,14 @@
 #endif
 
 #else
-#define BUILD_TIMESTAMP __DATE__ " " __TIME__
 
 #ifndef BUILD_SVN_REVISION
 #define BUILD_SVN_REVISION 0
 #endif
 #endif
 
+#define BUILD_TIMESTAMP _T(__DATE__) _T(" ") _T(__TIME__)
+
 // If the BUILD_SVN_REVISION happens to be negative, the build is assumed to be a public-release build (ie. not prerel)
 // So manually edit build/svn-revision.h to match that, when doing such a build, or add some other magic to do that.
 
@@ -84,7 +85,7 @@ struct VersionInfoStruct {
 		IsDebug = false;
 #endif
 		SvnRev = BUILD_SVN_REVISION;
-		BuildTime = _T(BUILD_TIMESTAMP);
+		BuildTime = BUILD_TIMESTAMP;
 		BuildCredit = _T(BUILD_CREDIT);
 
 		if (SvnRev > 0)