diff --git a/Text/TeXMath/OMML.hs b/Text/TeXMath/OMML.hs
--- a/Text/TeXMath/OMML.hs
+++ b/Text/TeXMath/OMML.hs
@@ -171,7 +171,7 @@
                                   ] ]
 
    EIdentifier x    -> [str [] x]
-   EMathOperator x  -> [str [] x]
+   EMathOperator x  -> [makeText TextNormal x]
    EStretchy x      -> showExp x  -- no support for stretchy in OMML
    ESymbol _ x      -> [str [] x]
    ESpace "0.167em" -> [str [] "\x2009"]
diff --git a/tests/08.omml b/tests/08.omml
--- a/tests/08.omml
+++ b/tests/08.omml
@@ -111,7 +111,9 @@
       <m:t>,</m:t>
     </m:r>
     <m:r>
-      <m:rPr />
+      <m:rPr>
+        <m:sty m:val="p" />
+      </m:rPr>
       <m:t>arg</m:t>
     </m:r>
     <m:r>
@@ -145,7 +147,9 @@
       <m:t>n</m:t>
     </m:r>
     <m:r>
-      <m:rPr />
+      <m:rPr>
+        <m:sty m:val="p" />
+      </m:rPr>
       <m:t>arg</m:t>
     </m:r>
     <m:r>
diff --git a/tests/09.omml b/tests/09.omml
--- a/tests/09.omml
+++ b/tests/09.omml
@@ -7,7 +7,9 @@
     <m:limLow>
       <m:e>
         <m:r>
-          <m:rPr />
+          <m:rPr>
+            <m:sty m:val="p" />
+          </m:rPr>
           <m:t>lim</m:t>
         </m:r>
       </m:e>
diff --git a/tests/10.omml b/tests/10.omml
--- a/tests/10.omml
+++ b/tests/10.omml
@@ -94,7 +94,9 @@
           </m:fPr>
           <m:num>
             <m:r>
-              <m:rPr />
+              <m:rPr>
+                <m:sty m:val="p" />
+              </m:rPr>
               <m:t>sin</m:t>
             </m:r>
             <m:r>
diff --git a/tests/sphere_volume.omml b/tests/sphere_volume.omml
--- a/tests/sphere_volume.omml
+++ b/tests/sphere_volume.omml
@@ -178,7 +178,9 @@
             </m:sup>
           </m:sSup>
           <m:r>
-            <m:rPr />
+            <m:rPr>
+              <m:sty m:val="p" />
+            </m:rPr>
             <m:t>sin</m:t>
           </m:r>
           <m:r>
@@ -299,7 +301,9 @@
             </m:sup>
           </m:nary>
           <m:r>
-            <m:rPr />
+            <m:rPr>
+              <m:sty m:val="p" />
+            </m:rPr>
             <m:t>sin</m:t>
           </m:r>
           <m:r>
@@ -420,7 +424,9 @@
             <m:t>−</m:t>
           </m:r>
           <m:r>
-            <m:rPr />
+            <m:rPr>
+              <m:sty m:val="p" />
+            </m:rPr>
             <m:t>cos</m:t>
           </m:r>
           <m:r>
diff --git a/tests/subsup.omml b/tests/subsup.omml
--- a/tests/subsup.omml
+++ b/tests/subsup.omml
@@ -47,7 +47,9 @@
     <m:limLow>
       <m:e>
         <m:r>
-          <m:rPr />
+          <m:rPr>
+            <m:sty m:val="p" />
+          </m:rPr>
           <m:t>min</m:t>
         </m:r>
       </m:e>
@@ -61,7 +63,9 @@
     <m:limLow>
       <m:e>
         <m:r>
-          <m:rPr />
+          <m:rPr>
+            <m:sty m:val="p" />
+          </m:rPr>
           <m:t>max</m:t>
         </m:r>
       </m:e>
@@ -75,7 +79,9 @@
     <m:limLow>
       <m:e>
         <m:r>
-          <m:rPr />
+          <m:rPr>
+            <m:sty m:val="p" />
+          </m:rPr>
           <m:t>det</m:t>
         </m:r>
       </m:e>
@@ -89,7 +95,9 @@
     <m:limLow>
       <m:e>
         <m:r>
-          <m:rPr />
+          <m:rPr>
+            <m:sty m:val="p" />
+          </m:rPr>
           <m:t>Pr</m:t>
         </m:r>
       </m:e>
@@ -103,7 +111,9 @@
     <m:limLow>
       <m:e>
         <m:r>
-          <m:rPr />
+          <m:rPr>
+            <m:sty m:val="p" />
+          </m:rPr>
           <m:t>gcd</m:t>
         </m:r>
       </m:e>
diff --git a/texmath.cabal b/texmath.cabal
--- a/texmath.cabal
+++ b/texmath.cabal
@@ -1,5 +1,5 @@
 Name:                texmath
-Version:             0.6.1.3
+Version:             0.6.1.4
 Cabal-Version:       >= 1.6
 Build-type:          Custom
 Synopsis:            Conversion of LaTeX math formulas to MathML or OMML.