diff --git a/Makefile b/Makefile
index b6a8be24..73a1e3de 100644
--- a/Makefile
+++ b/Makefile
@@ -21,13 +21,12 @@ SOURCES		:=	source source/libwiigui source/images source/fonts source/sounds \
 				source/usbloader source/xml source/network source/settings source/prompts \
 				source/ramdisc source/wad source/banner source/cheats source/homebrewboot
 INCLUDES	:=	source
-SVNDEV		:=	-D'SVN_REV="$(shell svnversion -n ..)"'
 
 #---------------------------------------------------------------------------------
 # options for code generation
 #---------------------------------------------------------------------------------
 
-CFLAGS		=	-g -O2 -save-temps -Wall $(SVNDEV) $(MACHDEP) $(INCLUDE)
+CFLAGS		=	-g -O2 -save-temps -Wall $(MACHDEP) $(INCLUDE)
 CXXFLAGS	=	-Xassembler -aln=$@.lst $(CFLAGS)
 LDFLAGS		=	-g $(MACHDEP) -Wl,-Map,$(notdir $@).map,--section-start,.init=0x80c00000
 
@@ -124,6 +123,7 @@ release:
 else
 
 DEPENDS	:=	$(OFILES:.o=.d)
+SVNREV	:=	$(shell ../svnrev.sh)
 
 #---------------------------------------------------------------------------------
 # main targets
diff --git a/source/network/networkops.cpp b/source/network/networkops.cpp
index 9edb91a0..b6c35564 100644
--- a/source/network/networkops.cpp
+++ b/source/network/networkops.cpp
@@ -16,6 +16,7 @@
 #include "settings/cfg.h"
 #include "main.h"
 #include "http.h"
+#include "svnrev.h"
 
 #define PORT            4299
 
diff --git a/source/prompts/PromptWindows.cpp b/source/prompts/PromptWindows.cpp
index 8e8dd510..b241fc3c 100644
--- a/source/prompts/PromptWindows.cpp
+++ b/source/prompts/PromptWindows.cpp
@@ -28,6 +28,7 @@
 #include "wad/wad.h"
 #include "unzip/unzip.h"
 #include "zlib.h"
+#include "svnrev.h"
 
 
 /*** Variables that are also used extern ***/
diff --git a/svnrev.sh b/svnrev.sh
new file mode 100644
index 00000000..5632717a
--- /dev/null
+++ b/svnrev.sh
@@ -0,0 +1,17 @@
+#! /bin/sh
+#
+a=$(svnversion -n ..)
+[ -n "$a" ] || a=$(SubWCRev .. | tr -d '\n' | sed 's/[^0-9]*\([0-9]*\).*/\1/')
+
+[ -f ../source/svnrev.h ] || touch ../source/svnrev.h
+
+b=$(cat ../source/svnrev.h | tr -d '\n' | sed 's/[^0-9]*\([0-9]*\).*/\1/')
+
+if [ $a -ne $b ]; then
+	echo '#ifndef SVNREV_H' > ../source/svnrev.h
+	echo '  #define SVNREV_H' >> ../source/svnrev.h
+	echo '  #define SVN_REV "'$a'"' >> ../source/svnrev.h
+	echo '#endif /* SVNREV_H */' >> ../source/svnrev.h
+	echo 'svnrev.h changed' >&2
+fi
+echo $a