diff --git a/gcc/lto-symtab.c b/gcc/lto-symtab.c
index d101449..c907723 100644
--- a/gcc/lto-symtab.c
+++ b/gcc/lto-symtab.c
@@ -648,9 +648,13 @@ lto_symtab_merge_decls_1 (void **slot, void *data ATTRIBUTE_UNUSED)
 
   /* Assert it's the only one.  */
   if (prevailing)
-    for (e = prevailing->next; e; e = e->next)
-      gcc_assert (e->resolution != LDPR_PREVAILING_DEF_IRONLY
-		  && e->resolution != LDPR_PREVAILING_DEF);
+      for (e = prevailing->next; e; e = e->next)
+	{
+	  if (e->resolution != LDPR_PREVAILING_DEF_IRONLY
+	      && e->resolution != LDPR_PREVAILING_DEF)
+	    fatal_error ("multiple prevailing defs for %qE", 
+			    DECL_NAME (prevailing->decl));
+	}
 
   /* If there's not a prevailing symbol yet it's an external reference.
      Happens a lot during ltrans.  Choose the first symbol with a