diff --git a/starmath/source/mathtype.cxx b/starmath/source/mathtype.cxx
index 4df34fa1714e..518f29fc5b40 100644
--- a/starmath/source/mathtype.cxx
+++ b/starmath/source/mathtype.cxx
@@ -45,6 +45,7 @@ void MathType::Init()
     stored in the document
     */
     MathTypeFont aFont;
+    aUserStyles.reserve(11);
     for(sal_uInt8 i=1;i<=11;i++)
     {
         aFont.nTface = i+128;
@@ -540,7 +541,7 @@ void MathTypeFont::AppendStyleToText(OUString &rRet)
 void MathType::TypeFaceToString(OUString &rTxt,sal_uInt8 nFace)
 {
     MathTypeFont aFont(nFace);
-    MathTypeFontSet::iterator aItr = aUserStyles.find(aFont);
+    auto aItr = aUserStyles.find(aFont);
     if (aItr != aUserStyles.end())
         aFont.nStyle = aItr->nStyle;
     aFont.AppendStyleToText(rTxt);
diff --git a/starmath/source/mathtype.hxx b/starmath/source/mathtype.hxx
index 4293b1e0608f..cd06cfcddf87 100644
--- a/starmath/source/mathtype.hxx
+++ b/starmath/source/mathtype.hxx
@@ -21,7 +21,7 @@
 
 #include <node.hxx>
 
-#include <set>
+#include <o3tl/sorted_vector.hxx>
 
 class SfxMedium;
 class SotStorage;
@@ -46,7 +46,7 @@ struct LessMathTypeFont
     }
 };
 
-typedef ::std::set< MathTypeFont, LessMathTypeFont > MathTypeFontSet;
+typedef o3tl::sorted_vector< MathTypeFont, LessMathTypeFont > MathTypeFontSet;
 
 class MathType
 {