diff --git a/src/errors.h b/src/errors.h
index baf36d5..975e033 100644
--- a/src/errors.h
+++ b/src/errors.h
@@ -3532,18 +3532,20 @@
 EXTERN char e_cannot_use_an_object_variable_except_with_the_new_method_str[]
 	INIT(= N_("E1390: Cannot use an object variable \"this.%s\" except with the \"new\" method"));
 #endif
+// E1391 - E1499 unused (reserved for Vim9 class support)
 EXTERN char e_cannot_mix_positional_and_non_positional_str[]
-	INIT(= N_("E1400: Cannot mix positional and non-positional arguments: %s"));
+	INIT(= N_("E1500: Cannot mix positional and non-positional arguments: %s"));
 EXTERN char e_fmt_arg_nr_unused_str[]
-	INIT(= N_("E1401: format argument %d unused in $-style format: %s"));
+	INIT(= N_("E1501: format argument %d unused in $-style format: %s"));
 EXTERN char e_positional_num_field_spec_reused_str_str[]
-	INIT(= N_("E1402: Positional argument %d used as field width reused as different type: %s/%s"));
+	INIT(= N_("E1502: Positional argument %d used as field width reused as different type: %s/%s"));
 EXTERN char e_positional_nr_out_of_bounds_str[]
-	INIT(= N_("E1403: Positional argument %d out of bounds: %s"));
+	INIT(= N_("E1503: Positional argument %d out of bounds: %s"));
 EXTERN char e_positional_arg_num_type_inconsistent_str_str[]
-	INIT(= N_("E1404: Positional argument %d type used inconsistently: %s/%s"));
+	INIT(= N_("E1504: Positional argument %d type used inconsistently: %s/%s"));
 EXTERN char e_invalid_format_specifier_str[]
-	INIT(= N_("E1405: Invalid format specifier: %s"));
+	INIT(= N_("E1505: Invalid format specifier: %s"));
 EXTERN char e_aptypes_is_null_nr_str[]
-	INIT(= "E1408: Internal error: ap_types or ap_types[idx] is NULL: %d: %s");
-// E1391 - E1399 unused
+	INIT(= "E1520: Internal error: ap_types or ap_types[idx] is NULL: %d: %s");
+
+// E1506 - E1519 unused
diff --git a/src/testdir/test_format.vim b/src/testdir/test_format.vim
index f665d15..af364c2 100644
--- a/src/testdir/test_format.vim
+++ b/src/testdir/test_format.vim
@@ -107,65 +107,65 @@
 
   call v9.CheckLegacyAndVim9Failure(["call printf('%1$d%2$d', 1, 3, 4)"], "E767:")
 
-  call v9.CheckLegacyAndVim9Failure(["call printf('%2$d%d', 1, 3)"], "E1400:")
-  call v9.CheckLegacyAndVim9Failure(["call printf('%d%2$d', 1, 3)"], "E1400:")
-  call v9.CheckLegacyAndVim9Failure(["call printf('%2$*1$d%d', 1, 3)"], "E1400:")
-  call v9.CheckLegacyAndVim9Failure(["call printf('%d%2$*1$d', 1, 3)"], "E1400:")
-  call v9.CheckLegacyAndVim9Failure(["call printf('%2$.*1$d%d', 1, 3)"], "E1400:")
-  call v9.CheckLegacyAndVim9Failure(["call printf('%d%2$.*1$d', 1, 3)"], "E1400:")
-  call v9.CheckLegacyAndVim9Failure(["call printf('%1$%')"], "E1400:")
-  call v9.CheckLegacyAndVim9Failure(["call printf('%1$')"], "E1400:")
-  call v9.CheckLegacyAndVim9Failure(["call printf('%1$_')"], "E1400:")
-  call v9.CheckLegacyAndVim9Failure(["call printf('%1$*3$.*d', 3)"], "E1400:")
-  call v9.CheckLegacyAndVim9Failure(["call printf('%1$*.*2$d', 3)"], "E1400:")
-  call v9.CheckLegacyAndVim9Failure(["call printf('%1$*.*d', 3)"], "E1400:")
-  call v9.CheckLegacyAndVim9Failure(["call printf('%*.*1$d', 3)"], "E1400:")
-  call v9.CheckLegacyAndVim9Failure(["call printf('%*1$.*d', 3)"], "E1400:")
-  call v9.CheckLegacyAndVim9Failure(["call printf('%*1$.*1$d', 3)"], "E1400:")
+  call v9.CheckLegacyAndVim9Failure(["call printf('%2$d%d', 1, 3)"], "E1500:")
+  call v9.CheckLegacyAndVim9Failure(["call printf('%d%2$d', 1, 3)"], "E1500:")
+  call v9.CheckLegacyAndVim9Failure(["call printf('%2$*1$d%d', 1, 3)"], "E1500:")
+  call v9.CheckLegacyAndVim9Failure(["call printf('%d%2$*1$d', 1, 3)"], "E1500:")
+  call v9.CheckLegacyAndVim9Failure(["call printf('%2$.*1$d%d', 1, 3)"], "E1500:")
+  call v9.CheckLegacyAndVim9Failure(["call printf('%d%2$.*1$d', 1, 3)"], "E1500:")
+  call v9.CheckLegacyAndVim9Failure(["call printf('%1$%')"], "E1500:")
+  call v9.CheckLegacyAndVim9Failure(["call printf('%1$')"], "E1500:")
+  call v9.CheckLegacyAndVim9Failure(["call printf('%1$_')"], "E1500:")
+  call v9.CheckLegacyAndVim9Failure(["call printf('%1$*3$.*d', 3)"], "E1500:")
+  call v9.CheckLegacyAndVim9Failure(["call printf('%1$*.*2$d', 3)"], "E1500:")
+  call v9.CheckLegacyAndVim9Failure(["call printf('%1$*.*d', 3)"], "E1500:")
+  call v9.CheckLegacyAndVim9Failure(["call printf('%*.*1$d', 3)"], "E1500:")
+  call v9.CheckLegacyAndVim9Failure(["call printf('%*1$.*d', 3)"], "E1500:")
+  call v9.CheckLegacyAndVim9Failure(["call printf('%*1$.*1$d', 3)"], "E1500:")
 
-  call v9.CheckLegacyAndVim9Failure(["call printf('%2$d', 3, 3)"], "E1401:")
+  call v9.CheckLegacyAndVim9Failure(["call printf('%2$d', 3, 3)"], "E1501:")
 
-  call v9.CheckLegacyAndVim9Failure(["call printf('%2$*1$d %1$ld', 3, 3)"], "E1402:")
-  call v9.CheckLegacyAndVim9Failure(["call printf('%1$s %1$*1$d', 3)"], "E1402:")
-  call v9.CheckLegacyAndVim9Failure(["call printf('%1$p %1$*1$d', 3)"], "E1402:")
-  call v9.CheckLegacyAndVim9Failure(["call printf('%1$f %1$*1$d', 3)"], "E1402:")
-  call v9.CheckLegacyAndVim9Failure(["call printf('%1$lud %1$*1$d', 3)"], "E1402:")
-  call v9.CheckLegacyAndVim9Failure(["call printf('%1$llud %1$*1$d', 3)"], "E1402:")
-  call v9.CheckLegacyAndVim9Failure(["call printf('%1$lld %1$*1$d', 3)"], "E1402:")
-  call v9.CheckLegacyAndVim9Failure(["call printf('%1$s %1$*1$d', 3)"], "E1402:")
-  call v9.CheckLegacyAndVim9Failure(["call printf('%1$c %1$*1$d', 3)"], "E1402:")
-  call v9.CheckLegacyAndVim9Failure(["call printf('%1$ld %1$*1$d', 3)"], "E1402:")
-  call v9.CheckLegacyAndVim9Failure(["call printf('%1$ld %2$*1$d', 3, 3)"], "E1402:")
-  call v9.CheckLegacyAndVim9Failure(["call printf('%1$*1$ld', 3)"], "E1402:")
-  call v9.CheckLegacyAndVim9Failure(["call printf('%1$*1$.*1$ld', 3)"], "E1402:")
+  call v9.CheckLegacyAndVim9Failure(["call printf('%2$*1$d %1$ld', 3, 3)"], "E1502:")
+  call v9.CheckLegacyAndVim9Failure(["call printf('%1$s %1$*1$d', 3)"], "E1502:")
+  call v9.CheckLegacyAndVim9Failure(["call printf('%1$p %1$*1$d', 3)"], "E1502:")
+  call v9.CheckLegacyAndVim9Failure(["call printf('%1$f %1$*1$d', 3)"], "E1502:")
+  call v9.CheckLegacyAndVim9Failure(["call printf('%1$lud %1$*1$d', 3)"], "E1502:")
+  call v9.CheckLegacyAndVim9Failure(["call printf('%1$llud %1$*1$d', 3)"], "E1502:")
+  call v9.CheckLegacyAndVim9Failure(["call printf('%1$lld %1$*1$d', 3)"], "E1502:")
+  call v9.CheckLegacyAndVim9Failure(["call printf('%1$s %1$*1$d', 3)"], "E1502:")
+  call v9.CheckLegacyAndVim9Failure(["call printf('%1$c %1$*1$d', 3)"], "E1502:")
+  call v9.CheckLegacyAndVim9Failure(["call printf('%1$ld %1$*1$d', 3)"], "E1502:")
+  call v9.CheckLegacyAndVim9Failure(["call printf('%1$ld %2$*1$d', 3, 3)"], "E1502:")
+  call v9.CheckLegacyAndVim9Failure(["call printf('%1$*1$ld', 3)"], "E1502:")
+  call v9.CheckLegacyAndVim9Failure(["call printf('%1$*1$.*1$ld', 3)"], "E1502:")
 
-  call v9.CheckLegacyAndVim9Failure(["call printf('%1$d%2$d', 3)"], "E1403:")
+  call v9.CheckLegacyAndVim9Failure(["call printf('%1$d%2$d', 3)"], "E1503:")
 
-  call v9.CheckLegacyAndVim9Failure(["call printf('%1$d %1$s', 3)"], "E1404:")
-  call v9.CheckLegacyAndVim9Failure(["call printf('%1$ld %1$s', 3)"], "E1404:")
-  call v9.CheckLegacyAndVim9Failure(["call printf('%1$ud %1$d', 3)"], "E1404:")
-  call v9.CheckLegacyAndVim9Failure(["call printf('%1$s %1$f', 3.0)"], "E1404:")
-  call v9.CheckLegacyAndVim9Failure(["call printf('%1$*1$d %1$ld', 3)"], "E1404:")
-  call v9.CheckLegacyAndVim9Failure(["call printf('%1$s %1$d', 3)"], "E1404:")
-  call v9.CheckLegacyAndVim9Failure(["call printf('%1$p %1$d', 3)"], "E1404:")
-  call v9.CheckLegacyAndVim9Failure(["call printf('%1$f %1$d', 3)"], "E1404:")
-  call v9.CheckLegacyAndVim9Failure(["call printf('%1$lud %1$d', 3)"], "E1404:")
-  call v9.CheckLegacyAndVim9Failure(["call printf('%1$llud %1$d', 3)"], "E1404:")
-  call v9.CheckLegacyAndVim9Failure(["call printf('%1$lld %1$d', 3)"], "E1404:")
-  call v9.CheckLegacyAndVim9Failure(["call printf('%1$s %1$d', 3)"], "E1404:")
-  call v9.CheckLegacyAndVim9Failure(["call printf('%1$c %1$d', 3)"], "E1404:")
-  call v9.CheckLegacyAndVim9Failure(["call printf('%1$ld %1$d', 3)"], "E1404:")
+  call v9.CheckLegacyAndVim9Failure(["call printf('%1$d %1$s', 3)"], "E1504:")
+  call v9.CheckLegacyAndVim9Failure(["call printf('%1$ld %1$s', 3)"], "E1504:")
+  call v9.CheckLegacyAndVim9Failure(["call printf('%1$ud %1$d', 3)"], "E1504:")
+  call v9.CheckLegacyAndVim9Failure(["call printf('%1$s %1$f', 3.0)"], "E1504:")
+  call v9.CheckLegacyAndVim9Failure(["call printf('%1$*1$d %1$ld', 3)"], "E1504:")
+  call v9.CheckLegacyAndVim9Failure(["call printf('%1$s %1$d', 3)"], "E1504:")
+  call v9.CheckLegacyAndVim9Failure(["call printf('%1$p %1$d', 3)"], "E1504:")
+  call v9.CheckLegacyAndVim9Failure(["call printf('%1$f %1$d', 3)"], "E1504:")
+  call v9.CheckLegacyAndVim9Failure(["call printf('%1$lud %1$d', 3)"], "E1504:")
+  call v9.CheckLegacyAndVim9Failure(["call printf('%1$llud %1$d', 3)"], "E1504:")
+  call v9.CheckLegacyAndVim9Failure(["call printf('%1$lld %1$d', 3)"], "E1504:")
+  call v9.CheckLegacyAndVim9Failure(["call printf('%1$s %1$d', 3)"], "E1504:")
+  call v9.CheckLegacyAndVim9Failure(["call printf('%1$c %1$d', 3)"], "E1504:")
+  call v9.CheckLegacyAndVim9Failure(["call printf('%1$ld %1$d', 3)"], "E1504:")
 
-  call v9.CheckLegacyAndVim9Failure(["call printf('%1$.2$d', 3)"], "E1405:")
-  call v9.CheckLegacyAndVim9Failure(["call printf('%01$d', 3)"], "E1405:")
-  call v9.CheckLegacyAndVim9Failure(["call printf('%01$0d', 3)"], "E1405:")
-  call v9.CheckLegacyAndVim9Failure(["call printf('%1$*2d', 3)"], "E1405:")
-  call v9.CheckLegacyAndVim9Failure(["call printf('%1$*3.*2$d', 3)"], "E1405:")
-  call v9.CheckLegacyAndVim9Failure(["call printf('%1$*3$.2$d', 3)"], "E1405:")
-  call v9.CheckLegacyAndVim9Failure(["call printf('%1$*3$.*2d', 3)"], "E1405:")
-  call v9.CheckLegacyAndVim9Failure(["call printf('%1$1$.5d', 5)"], "E1405:")
-  call v9.CheckLegacyAndVim9Failure(["call printf('%1$5.1$d', 5)"], "E1405:")
-  call v9.CheckLegacyAndVim9Failure(["call printf('%1$1$.1$d', 5)"], "E1405:")
+  call v9.CheckLegacyAndVim9Failure(["call printf('%1$.2$d', 3)"], "E1505:")
+  call v9.CheckLegacyAndVim9Failure(["call printf('%01$d', 3)"], "E1505:")
+  call v9.CheckLegacyAndVim9Failure(["call printf('%01$0d', 3)"], "E1505:")
+  call v9.CheckLegacyAndVim9Failure(["call printf('%1$*2d', 3)"], "E1505:")
+  call v9.CheckLegacyAndVim9Failure(["call printf('%1$*3.*2$d', 3)"], "E1505:")
+  call v9.CheckLegacyAndVim9Failure(["call printf('%1$*3$.2$d', 3)"], "E1505:")
+  call v9.CheckLegacyAndVim9Failure(["call printf('%1$*3$.*2d', 3)"], "E1505:")
+  call v9.CheckLegacyAndVim9Failure(["call printf('%1$1$.5d', 5)"], "E1505:")
+  call v9.CheckLegacyAndVim9Failure(["call printf('%1$5.1$d', 5)"], "E1505:")
+  call v9.CheckLegacyAndVim9Failure(["call printf('%1$1$.1$d', 5)"], "E1505:")
 endfunc
 
 func Test_printf_pos_float()
@@ -296,9 +296,9 @@
   call v9.CheckLegacyAndVim9Failure(['echo printf("%1$d", [])'], 'E745:')
   call v9.CheckLegacyAndVim9Failure(['echo printf("%1$d", 1, 2)'], 'E767:')
   call v9.CheckLegacyAndVim9Failure(['echo printf("%*d", 1)'], 'E766:')
-  call v9.CheckLegacyAndVim9Failure(['echo printf("%1$s")'], 'E1403:')
+  call v9.CheckLegacyAndVim9Failure(['echo printf("%1$s")'], 'E1503:')
   call v9.CheckLegacyAndVim9Failure(['echo printf("%1$d", 1.2)'], 'E805:')
-  call v9.CheckLegacyAndVim9Failure(['echo printf("%1$f")'], 'E1403:')
+  call v9.CheckLegacyAndVim9Failure(['echo printf("%1$f")'], 'E1503:')
 endfunc
 
 func Test_printf_pos_64bit()
diff --git a/src/version.c b/src/version.c
index dade6d2..0bb2239 100644
--- a/src/version.c
+++ b/src/version.c
@@ -700,6 +700,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1950,
+/**/
     1949,
 /**/
     1948,