diff --git a/autoload/vue.vim b/autoload/vue.vim
index 0f08ba6..f4fe80f 100644
--- a/autoload/vue.vim
+++ b/autoload/vue.vim
@@ -263,6 +263,10 @@ endfunction
 " Load all syntax files in 'runtimepath'
 " Useful if there is no default syntax file provided by vim
 function! vue#LoadFullSyntax(group, syntax)
+  if empty(globpath(&runtimepath, 'syntax/'.a:syntax.'.vim'))
+    call vue#Warn(a:syntax.': syntax not found in runtimepath')
+    return
+  endif
   call vue#Log(a:syntax.': load full')
   call s:SetCurrentSyntax(a:syntax)
   execute 'syntax include '.a:group.' syntax/'.a:syntax.'.vim'
diff --git a/indent/vue.vim b/indent/vue.vim
index aece7f8..f66bd3d 100644
--- a/indent/vue.vim
+++ b/indent/vue.vim
@@ -75,6 +75,11 @@ function! s:GetBlockIndent(syntax)
   let indentexpr = get(s:indent, syntax) 
   if !empty(indentexpr)
     let ind = eval(indentexpr)
+  elseif has_key(s:indent, syntax)
+    " No indent file for syntax in config, keep indent as cindent may break
+    " languages like pug or toml
+    call vue#LogWithLnum('indentexpr not found for '.syntax.', keep indent')
+    let ind = -1
   else
     call vue#LogWithLnum('indentexpr not found for '.syntax.', use cindent')
     let ind = cindent(v:lnum)
diff --git a/test/cases/no-syntax-indent-file.vim b/test/cases/no-syntax-indent-file.vim
new file mode 100644
index 0000000..ef233b3
--- /dev/null
+++ b/test/cases/no-syntax-indent-file.vim
@@ -0,0 +1,15 @@
+" postcss has no syntax or indent file, toml has no indent file. They have
+" their blocks and keep indent
+let g:vim_vue_plugin_config = {
+      \'syntax': {
+      \   'template': ['html'],
+      \   'style': ['css', 'postcss'],
+      \   'i18n': ['toml'],
+      \},
+      \}
+
+function! Check()
+  call ExpectBlock('color: blue', 'style', 'postcss', 'postcssStyleBlock')
+  call ExpectBlock('hello', 'i18n', 'toml', 'tomlI18nBlock')
+  call ExpectIndentEachLine()
+endfunction
diff --git a/test/cases/no-syntax-indent-file.vue b/test/cases/no-syntax-indent-file.vue
new file mode 100644
index 0000000..4c68d4a
--- /dev/null
+++ b/test/cases/no-syntax-indent-file.vue
@@ -0,0 +1,15 @@
+<template>
+  <div>x</div>
+</template>
+
+<style lang="postcss">
+p
+  color: red
+  a
+    color: blue
+</style>
+
+<i18n lang="toml">
+[en]
+  hello = "hi"
+</i18n>
diff --git a/test/run.vim b/test/run.vim
index 1179998..55e6eaa 100644
--- a/test/run.vim
+++ b/test/run.vim
@@ -92,7 +92,8 @@ function! ExpectTag(lnum, tag)
 endfunction
 
 " Call GetVueIndent() for each non-blank line from line 2 as when typing it,
-" which shows errors hidden by 'indentexpr', and check the indent
+" which shows errors hidden by 'indentexpr', and check the indent. -1 keeps
+" the indent
 function! ExpectIndentEachLine()
   for lnum in range(2, line('$'))
     if getline(lnum) =~ '^\s*$'
@@ -101,7 +102,8 @@ function! ExpectIndentEachLine()
     call cursor(lnum, 1)
     let v:lnum = lnum
     try
-      call ExpectEqual(GetVueIndent(), indent(lnum),
+      let ind = GetVueIndent()
+      call ExpectEqual(ind == -1 ? indent(lnum) : ind, indent(lnum),
             \ printf('GetVueIndent() at line %d', lnum))
     catch
       call Fail(printf('GetVueIndent() at line %d: %s', lnum, v:exception))