diff --git a/polymer/synthesis.sh b/polymer/synthesis.sh
index db9bc934e..cb8b09269 100755
--- a/polymer/synthesis.sh
+++ b/polymer/synthesis.sh
@@ -73,6 +73,8 @@ then
     echo rm mapster32.debug.exe
     rm mapster32.debug.exe
 
+    # throw the svn revision into a header.  this is ugly.
+    echo "const char *s_buildRev = \"r$head\";" > source/rev.h
     # clean the tree and build debug first
     echo "${make[@]}" RELEASE=0 $clean all
     "${make[@]}" RELEASE=0 $clean all