diff --git a/src/eval.c b/src/eval.c
index 0d83f1d..34fdd67 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -9278,7 +9278,8 @@
 	assert_error(&ga);
 	ga_clear(&ga);
     }
-    else if (strstr((char *)vimvars[VV_EXCEPTION].vv_str, error) == NULL)
+    else if (error != NULL
+	    && strstr((char *)vimvars[VV_EXCEPTION].vv_str, error) == NULL)
     {
 	prepare_assert_error(&ga);
 	fill_assert_error(&ga, &argvars[1], NULL, &argvars[0],
diff --git a/src/testdir/test_assert.vim b/src/testdir/test_assert.vim
index 25337a5..70a303f 100644
--- a/src/testdir/test_assert.vim
+++ b/src/testdir/test_assert.vim
@@ -18,6 +18,25 @@
   call assert_equal([1, 2, 3], l)
 endfunc
 
+func Test_assert_exception()
+  try
+    nocommand
+  catch
+    call assert_exception('E492:')
+  endtry
+
+  try
+    nocommand
+  catch
+    try
+      " illegal argument, get NULL for error
+      call assert_exception([])
+    catch
+      call assert_exception('E730:')
+    endtry
+  endtry
+endfunc
+
 func Test_user_is_happy()
   smile
   sleep 300m
diff --git a/src/version.c b/src/version.c
index 843e741..30e6068 100644
--- a/src/version.c
+++ b/src/version.c
@@ -742,6 +742,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1136,
+/**/
     1135,
 /**/
     1134,