diff --git a/runtime/syntax/cmod.vim b/runtime/syntax/cmod.vim
index 3ba09dd2444477..750a60d3ce7951 100644
--- a/runtime/syntax/cmod.vim
+++ b/runtime/syntax/cmod.vim
@@ -57,19 +57,12 @@ syn cluster cPreProcGroup add=cmodAutodocReal
 
 " Default highlighting
 hi def link cmodAccess		Statement
-hi def link cmodCast		Statement
-hi def link cmodExceptions	Exception
 hi def link cmodOperator	Operator
 hi def link cmodStatement	Statement
 hi def link cmodModifier	Type
 hi def link cmodType		Type
 hi def link cmodStorageClass	StorageClass
 hi def link cmodStructure	Structure
-hi def link cmodBoolean		Boolean
-hi def link cmodConstant	Constant
-hi def link cmodRawStringDelimiter	Delimiter
-hi def link cmodRawString	String
-hi def link cmodNumber		Number
 
 let b:current_syntax = "cmod"