diff --git a/libbacktrace/ChangeLog b/libbacktrace/ChangeLog
index 255e2c8921e6..e7fdfd8e9403 100644
--- a/libbacktrace/ChangeLog
+++ b/libbacktrace/ChangeLog
@@ -1,3 +1,8 @@
+2018-11-27  Tom de Vries  <tdevries@suse.de>
+
+	* mmap.c (backtrace_vector_release): Same.
+	* unittest.c (test1): Add check.
+
 2018-11-27  Tom de Vries  <tdevries@suse.de>
 
 	* alloc.c (backtrace_vector_release): Handle vec->size == 0 using free
diff --git a/libbacktrace/mmap.c b/libbacktrace/mmap.c
index 32fcba623992..9f896a1bb998 100644
--- a/libbacktrace/mmap.c
+++ b/libbacktrace/mmap.c
@@ -321,5 +321,7 @@ backtrace_vector_release (struct backtrace_state *state,
   backtrace_free (state, (char *) vec->base + aligned, alc,
 		  error_callback, data);
   vec->alc = 0;
+  if (vec->size == 0)
+    vec->base = NULL;
   return 1;
 }
diff --git a/libbacktrace/unittest.c b/libbacktrace/unittest.c
index 576aa0809350..3471d78488d1 100644
--- a/libbacktrace/unittest.c
+++ b/libbacktrace/unittest.c
@@ -69,7 +69,7 @@ test1 (void)
 
   count = 0;
   res = backtrace_vector_release (state, &vec, error_callback, NULL);
-  failed = res != 1 || count != 0;
+  failed = res != 1 || count != 0 || vec.base != NULL;
 
   printf ("%s: unittest backtrace_vector_release size == 0\n",
 	  failed ? "FAIL": "PASS");