diff --git a/src/common/fileconf.cpp b/src/common/fileconf.cpp
index 639e9b089e..e26936b7a5 100644
--- a/src/common/fileconf.cpp
+++ b/src/common/fileconf.cpp
@@ -495,7 +495,7 @@ wxFileConfig::wxFileConfig(wxInputStream &inStream, wxMBConv& conv)
         char buf[1024];
         do
         {
-            inStream.Read(buf, WXSIZEOF(buf));
+            inStream.Read(buf, WXSIZEOF(buf)-1);  // leave room for the NULL
 
             const wxStreamError err = inStream.GetLastError();