diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 88fb3b4b2b5..ce11bc4ca0b 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2017-01-04  Alexandre Oliva <aoliva@redhat.com>
+
+	* input.c (assert_char_at_range): Default-initialize
+	actual_range.
+
 2017-01-04  Alexandre Oliva <aoliva@redhat.com>
 
 	* df-scan.c (df_ref_create_structure): Make regno unsigned,
diff --git a/gcc/input.c b/gcc/input.c
index 0294034114b..195f72e0619 100644
--- a/gcc/input.c
+++ b/gcc/input.c
@@ -2173,7 +2173,7 @@ assert_char_at_range (const location &loc,
   cpp_reader *pfile = test.m_parser;
   string_concat_db *concats = &test.m_concats;
 
-  source_range actual_range;
+  source_range actual_range = source_range();
   const char *err
     = get_source_range_for_char (pfile, concats, strloc, type, idx,
 				 &actual_range);