diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 9f6ec57e1fb..5e50e528ab2 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2002-04-17  Nick Clifton  <nickc@cambridge.redhat.com>
+
+	* gcc.c (read_specs): Detect and fail if an attempt is made to
+	rename a spec string to an already existing string.
+
 2002-04-17  Ulrich Weigand  <uweigand@de.ibm.com>
 
 	* config/s390/s390.c (legitimize_pic_address): Do not generate
diff --git a/gcc/gcc.c b/gcc/gcc.c
index 8fa6bb5979e..8e0106cdb5d 100644
--- a/gcc/gcc.c
+++ b/gcc/gcc.c
@@ -1862,8 +1862,9 @@ read_specs (filename, main_p)
 	    {
 	      int name_len;
 	      struct spec_list *sl;
+	      struct spec_list *newsl;
 
-	      /* Get original name */
+	      /* Get original name.  */
 	      p1 += sizeof "%rename";
 	      while (*p1 == ' ' || *p1 == '\t')
 		p1++;
@@ -1909,6 +1910,11 @@ read_specs (filename, main_p)
 	      if (strcmp (p1, p2) == 0)
 		continue;
 
+	      for (newsl = specs; newsl; newsl = newsl->next)
+		if (strcmp (newsl->name, p2) == 0)
+		  fatal ("%s: attempt to rename spec '%s' to already defined spec '%s'",
+		    filename, p1, p2);
+
 	      if (verbose_flag)
 		{
 		  notice ("rename spec %s to %s\n", p1, p2);