diff --git a/src/message.c b/src/message.c
index 7bb154d..9541528 100644
--- a/src/message.c
+++ b/src/message.c
@@ -4198,6 +4198,15 @@
 		default: break;
 	    }
 
+# if defined(FEAT_EVAL) && defined(FEAT_NUM64)
+	    switch (fmt_spec)
+	    {
+		case 'd': case 'u': case 'o': case 'x': case 'X':
+		    if (tvs != NULL && length_modifier == '\0')
+			length_modifier = 'L';
+	    }
+# endif
+
 	    /* get parameter value, do initial processing */
 	    switch (fmt_spec)
 	    {
diff --git a/src/testdir/test_expr.vim b/src/testdir/test_expr.vim
index 067dbf2..86c86c5 100644
--- a/src/testdir/test_expr.vim
+++ b/src/testdir/test_expr.vim
@@ -129,3 +129,9 @@
   call assert_equal("abcdefgi", &cpo)
   set cpo&vim
 endfunc
+
+function Test_printf_64bit()
+  if has('num64')
+    call assert_equal("123456789012345", printf('%d', 123456789012345))
+  endif
+endfunc
diff --git a/src/version.c b/src/version.c
index 6d75f76..301b406 100644
--- a/src/version.c
+++ b/src/version.c
@@ -759,6 +759,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2029,
+/**/
     2028,
 /**/
     2027,