diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index ca109d99911b..20c59e5f4c0c 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2004-05-31  Danny Smith  <dannysmith@users.sourceforge.net>
+
+	* c-incpath.c (add_path): Canonicalize paths to use '/' if
+	HAVE_DOS_BASED_FILESYSTEM.
+
 2004-05-31  Steven Bosscher  <stevenb@suse.de>
 
 	* tree-ssa-dom.c (record_equivalences_from_incoming_edge):
diff --git a/gcc/c-incpath.c b/gcc/c-incpath.c
index 8bd18c62b12d..2f00d62bb63a 100644
--- a/gcc/c-incpath.c
+++ b/gcc/c-incpath.c
@@ -327,6 +327,16 @@ add_path (char *path, int chain, int cxx_aware, bool user_supplied_p)
 {
   cpp_dir *p;
 
+#if defined (HAVE_DOS_BASED_FILE_SYSTEM)
+  /* Convert all backslashes to slashes.  The native CRT stat()
+     function does not recognise a directory that ends in a backslash
+     (unless it is a drive root dir, such "c:\").  Forward slashes,
+     trailing or otherwise, cause no problems for stat().  */
+  char* c;
+  for (c = path; *c; c++)
+    if (*c == '\\') *c = '/';
+#endif
+
   p = xmalloc (sizeof (cpp_dir));
   p->next = NULL;
   p->name = path;