diff --git a/src/nvim/api/autocmd.c b/src/nvim/api/autocmd.c
index 6a267103b4..e606322f24 100644
--- a/src/nvim/api/autocmd.c
+++ b/src/nvim/api/autocmd.c
@@ -114,7 +114,7 @@ Array nvim_get_autocmds(Dict(get_autocmds) *opts, Error *err)
     break;
   case kObjectTypeInteger:
     group = (int)opts->group.data.integer;
-    char *name = augroup_name(group);
+    char *name = group == 0 ? NULL : augroup_name(group);
     VALIDATE_INT(augroup_exists(name), "group", opts->group.data.integer, {
       goto cleanup;
     });
@@ -684,7 +684,7 @@ void nvim_del_augroup_by_id(Integer id, Error *err)
   FUNC_API_SINCE(9)
 {
   TRY_WRAP(err, {
-    char *name = augroup_name((int)id);
+    char *name = id == 0 ? NULL : augroup_name((int)id);
     augroup_del(name, false);
   });
 }
@@ -746,7 +746,7 @@ void nvim_exec_autocmds(Object event, Dict(exec_autocmds) *opts, Error *err)
     break;
   case kObjectTypeInteger:
     au_group = (int)opts->group.data.integer;
-    char *name = augroup_name(au_group);
+    char *name = au_group == 0 ? NULL : augroup_name(au_group);
     VALIDATE_INT(augroup_exists(name), "group", (int64_t)au_group, {
       goto cleanup;
     });
@@ -840,7 +840,7 @@ static int get_augroup_from_object(Object group, Error *err)
     return au_group;
   case kObjectTypeInteger:
     au_group = (int)group.data.integer;
-    char *name = augroup_name(au_group);
+    char *name = au_group == 0 ? NULL : augroup_name(au_group);
     VALIDATE_INT(augroup_exists(name), "group", (int64_t)au_group, {
       return AUGROUP_ERROR;
     });
diff --git a/test/functional/api/autocmd_spec.lua b/test/functional/api/autocmd_spec.lua
index b1e38e77a1..57390519de 100644
--- a/test/functional/api/autocmd_spec.lua
+++ b/test/functional/api/autocmd_spec.lua
@@ -39,6 +39,10 @@ describe('autocmd api', function()
       }))
       eq("Invalid 'event' item: expected String, got Array", pcall_err(meths.create_autocmd,
         {'FileType', {}}, {}))
+      eq("Invalid 'group': 0", pcall_err(meths.create_autocmd, 'FileType', {
+        group = 0,
+        command = 'ls',
+      }))
     end)
 
     it('doesnt leak when you use ++once', function()
@@ -308,6 +312,9 @@ describe('autocmd api', function()
       eq("Invalid 'group': 'bogus'", pcall_err(meths.get_autocmds, {
         group = 'bogus',
       }))
+      eq("Invalid 'group': 0", pcall_err(meths.get_autocmds, {
+        group = 0,
+      }))
       eq("Invalid 'group': expected String or Integer, got Array", pcall_err(meths.get_autocmds, {
         group = {},
       }))
@@ -725,6 +732,9 @@ describe('autocmd api', function()
       eq("Invalid 'group': expected String or Integer, got Array", pcall_err(meths.exec_autocmds, 'FileType', {
         group = {},
       }))
+      eq("Invalid 'group': 0", pcall_err(meths.exec_autocmds, 'FileType', {
+        group = 0,
+      }))
       eq("Invalid 'buffer': expected Integer, got Array", pcall_err(meths.exec_autocmds, 'FileType', {
         buffer = {},
       }))
@@ -1049,6 +1059,12 @@ describe('autocmd api', function()
 
       eq(false, exec_lua[[return pcall(vim.api.nvim_del_augroup_by_id, -12342)]])
       eq('Vim:E367: No such group: "--Deleted--"', pcall_err(meths.del_augroup_by_id, -12312))
+
+      eq(false, exec_lua[[return pcall(vim.api.nvim_del_augroup_by_id, 0)]])
+      eq('Vim:E367: No such group: "[NULL]"', pcall_err(meths.del_augroup_by_id, 0))
+
+      eq(false, exec_lua[[return pcall(vim.api.nvim_del_augroup_by_id, 12342)]])
+      eq('Vim:E367: No such group: "[NULL]"', pcall_err(meths.del_augroup_by_id, 12312))
     end)
 
     it('groups work with once', function()
@@ -1224,6 +1240,7 @@ describe('autocmd api', function()
       eq("Invalid 'event' item: expected String, got Array", pcall_err(meths.clear_autocmds, {
         event = {'FileType', {}}
       }))
+      eq("Invalid 'group': 0", pcall_err(meths.clear_autocmds, {group = 0}))
     end)
 
     it('should clear based on event + pattern', function()