diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 8a291ac4fa..1743bfa140 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,7 @@
+2013-06-18  Jan Kratochvil  <jan.kratochvil@redhat.com>
+
+	* dwarf2read.c (write_psymtabs_to_index): Ignore NULL PSYMTAB.
+
 2013-06-17  Pierre Muller  <muller@sourceware.org>
 
 	* corelow.c (core_open): Print GDB signal name instead of target
diff --git a/gdb/dwarf2read.c b/gdb/dwarf2read.c
index a902b70fd0..316bb861c0 100644
--- a/gdb/dwarf2read.c
+++ b/gdb/dwarf2read.c
@@ -21270,6 +21270,12 @@ write_psymtabs_to_index (struct objfile *objfile, const char *dir)
       struct psymtab_cu_index_map *map;
       void **slot;
 
+      /* CU of a shared file from 'dwz -m' may be unused by this main file.
+	 It may be referenced from a local scope but in such case it does not
+	 need to be present in .gdb_index.  */
+      if (psymtab == NULL)
+	continue;
+
       if (psymtab->user == NULL)
 	recursively_write_psymbols (objfile, psymtab, symtab, psyms_seen, i);