diff --git a/reactos/tools/wpp/CMakeLists.txt b/reactos/tools/wpp/CMakeLists.txt
index dd8d528834d..75a95217b72 100644
--- a/reactos/tools/wpp/CMakeLists.txt
+++ b/reactos/tools/wpp/CMakeLists.txt
@@ -3,8 +3,13 @@ if(MSVC)
     add_definitions(
         -Dsnprintf=_snprintf
         -Dstrtoull=_strtoui64
-        -Dstrtoll=_strtoi64
-        -Dvsnprintf=_vsnprintf)
+        -Dstrtoll=_strtoi64)
+
+    # VS 9 doesn't like this
+    if (NOT MSVC90)
+        add_definitions(
+            -Dvsnprintf=_vsnprintf)
+    endif()
 endif()
 
 list(APPEND SOURCE
@@ -15,4 +20,4 @@ list(APPEND SOURCE
 
 add_library(wpp ${SOURCE})
 
-add_dependencies(wpp build_header)
\ No newline at end of file
+add_dependencies(wpp build_header)