diff --git a/elegantbook.cls b/elegantbook.cls
index 15610b1..3001699 100644
--- a/elegantbook.cls
+++ b/elegantbook.cls
@@ -99,17 +99,11 @@
 \RequirePackage{anyfontsize}
 \ifdefstring{\ELEGANT@math}{newtxmath}{
 \RequirePackage{newtxmath}
-\DeclareSymbolFont{CMletters}     {OML}{cmm} {m}{it}%
-\DeclareSymbolFont{CMsymbols}     {OMS}{cmsy}{m}{n}%
-\DeclareSymbolFont{CMlargesymbols}{OMX}{cmex}{m}{n}%
-\let\intop\relax
-\let\sumop\relax
-\let\ointop\relax
-\let\prodop\relax
-\DeclareMathSymbol{\sumop}{\mathop}{CMlargesymbols}{"50}
-\DeclareMathSymbol{\intop}{\mathop}{CMlargesymbols}{"52}
-\DeclareMathSymbol{\ointop}{\mathop}{CMlargesymbols}{"48}
-\DeclareMathSymbol{\prodop}{\mathop}{CMlargesymbols}{"51}
+\let\intop\relax\let\sumop\relax\let\ointop\relax\let\prodop\relax
+\DeclareMathSymbol{\sumop}{\mathop}{largesymbols}{"50}
+\DeclareMathSymbol{\intop}{\mathop}{largesymbols}{"52}
+\DeclareMathSymbol{\ointop}{\mathop}{largesymbols}{"48}
+\DeclareMathSymbol{\prodop}{\mathop}{largesymbols}{"51}
 }{\relax}
 
 % ----- Handle Colors -----