diff --git a/data/syntax/c.xml b/data/syntax/c.xml
--- a/data/syntax/c.xml
+++ b/data/syntax/c.xml
@@ -1,16 +1,16 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <!DOCTYPE language SYSTEM "language.dtd"
 [
-    <!ENTITY int "(?:[0-9](?:'?[0-9]+)*)">
-    <!ENTITY hex_int "(?:[0-9A-Fa-f](?:'?[0-9A-Fa-f]+)*)">
+    <!ENTITY int "(?:[0-9]+)">
+    <!ENTITY hex_int "(?:[0-9A-Fa-f]+)">
     <!ENTITY exp_float "(?:[eE][+-]?&int;)">
     <!ENTITY exp_hexfloat "(?:[pP][-+]?&int;)">
 
     <!ENTITY ispphash "(?:#|&#37;\:|\?\?=)">
     <!ENTITY pphash "&ispphash;\s*">
 ]>
 <language name="C" section="Sources"
-          version="7" kateversion="5.0"
+          version="8" kateversion="5.0"
           indenter="cstyle"
           extensions="*.c;*.C;*.h"
           mimetype="text/x-csrc;text/x-c++src;text/x-chdr"
@@ -232,9 +232,9 @@
 
       <context name="Integer" attribute="Normal Text" lineEndContext="#pop" fallthrough="true" fallthroughContext="#pop">
         <RegExpr attribute="Hex" context="IntSuffix" String="0[xX]&hex_int;" />
-        <RegExpr attribute="Binary" context="IntSuffix" String="0[Bb][01](?:'?[01]+)*" />
-        <RegExpr attribute="Octal" context="IntSuffix" String="0(?:'?[0-7]+)+" />
-        <RegExpr attribute="Decimal" context="IntSuffix" String="0(?![xXbB0-9])|[1-9](?:'?[0-9]+)*" />
+        <RegExpr attribute="Binary" context="IntSuffix" String="0[Bb][01]+" />
+        <RegExpr attribute="Octal" context="IntSuffix" String="0[0-7]+" />
+        <RegExpr attribute="Decimal" context="IntSuffix" String="0(?![xXbB0-9])|[1-9][0-9]*" />
         <RegExpr attribute="Error" context="#pop" String="[._0-9A-Za-z']+" />
       </context>