diff --git a/src/message.c b/src/message.c
index f0d1806..0fb0013 100644
--- a/src/message.c
+++ b/src/message.c
@@ -1133,12 +1133,10 @@
     if (!(messages_flags_new & MESSAGES_HISTORY))
         return FAIL;
 
-    // "history" must be <= 10000
-    if (messages_history_new > 10000)
+    if (messages_history_new < 0 || messages_history_new > 10000)
         return FAIL;
 
-    // "wait" must be <= 10000
-    if (messages_wait_new > 10000)
+    if (messages_wait_new < 0 || messages_wait_new > 10000)
         return FAIL;
 
     msg_flags = messages_flags_new;
diff --git a/src/testdir/gen_opt_test.vim b/src/testdir/gen_opt_test.vim
index 74f5ae5..d1c721e 100644
--- a/src/testdir/gen_opt_test.vim
+++ b/src/testdir/gen_opt_test.vim
@@ -237,7 +237,9 @@
       \		'hit-enter,history:1,wait:1'],
       \		['xxx', 'history:500', 'hit-enter,history:-1',
       \		'hit-enter,history:10001', 'history:0,wait:10001',
-      \		'hit-enter']],
+      \		'hit-enter', 'history:10,wait:99999999999999999999',
+      \		'history:99999999999999999999,wait:10', 'wait:10',
+      \		'history:-10', 'history:10,wait:-10']],
       \ 'mkspellmem': [['10000,100,12'], ['', 'xxx', '10000,100']],
       \ 'mouse': [['', 'n', 'v', 'i', 'c', 'h', 'a', 'r', 'nvi'],
       \		['xxx', 'n,v,i']],
diff --git a/src/version.c b/src/version.c
index 6dc9a47..1333d9d 100644
--- a/src/version.c
+++ b/src/version.c
@@ -705,6 +705,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    913,
+/**/
     912,
 /**/
     911,