diff --git a/runtime/syntax/sm.vim b/runtime/syntax/sm.vim
index 8fdc14b..33a6772 100644
--- a/runtime/syntax/sm.vim
+++ b/runtime/syntax/sm.vim
@@ -56,36 +56,28 @@
 syn region smClause	matchgroup=Delimiter start="\$?." matchgroup=Delimiter end="\$\." contains=smElse,smClause,smVar,smClauseCont
 
 " Define the default highlighting.
-" For version 5.7 and earlier: only when not done already
-" For version 5.8 and later: only when an item doesn't have highlighting yet
-if version >= 508 || !exists("did_smil_syntax_inits")
-  if version < 508
-    let did_smil_syntax_inits = 1
-    command -nargs=+ HiLink hi link <args>
-  else
-    command -nargs=+ HiLink hi def link <args>
-  endif
+" Only when an item doesn't have highlighting yet
+command -nargs=+ HiLink hi def link <args>
 
-  HiLink smClause	Special
-  HiLink smClauseError	Error
-  HiLink smComment	Comment
-  HiLink smDefine	Statement
-  HiLink smElse		Delimiter
-  HiLink smHeader	Statement
-  HiLink smHeaderSep	String
-  HiLink smMesg		Special
-  HiLink smPrecedence	Number
-  HiLink smRewrite	Statement
-  HiLink smRewriteComment	Comment
-  HiLink smRewriteLhsToken	String
-  HiLink smRewriteLhsUser	Statement
-  HiLink smRewriteRhsToken	String
-  HiLink smRuleset	Preproc
-  HiLink smTrusted	Special
-  HiLink smVar		String
+HiLink smClause	Special
+HiLink smClauseError	Error
+HiLink smComment	Comment
+HiLink smDefine	Statement
+HiLink smElse		Delimiter
+HiLink smHeader	Statement
+HiLink smHeaderSep	String
+HiLink smMesg		Special
+HiLink smPrecedence	Number
+HiLink smRewrite	Statement
+HiLink smRewriteComment	Comment
+HiLink smRewriteLhsToken	String
+HiLink smRewriteLhsUser	Statement
+HiLink smRewriteRhsToken	String
+HiLink smRuleset	Preproc
+HiLink smTrusted	Special
+HiLink smVar		String
 
-  delcommand HiLink
-endif
+delcommand HiLink
 
 let b:current_syntax = "sm"