diff --git a/src/mathed/InsetMathDelim.cpp b/src/mathed/InsetMathDelim.cpp
index d32029b818..fab72db88d 100644
--- a/src/mathed/InsetMathDelim.cpp
+++ b/src/mathed/InsetMathDelim.cpp
@@ -190,15 +190,16 @@ void InsetMathDelim::mathematica(MathematicaStream & os) const
 void InsetMathDelim::mathmlize(MathMLStream & ms) const
 {
 	// Ignore the delimiter if: it is empty or only a space (one character).
+	const std::string attr = is_extracted_ ? "stretchy='false'" : "";
 	if (!left_.empty() && ((left_.size() == 1 && left_[0] != ' ') || left_.size() > 1)) {
 	    ms << MTag("mrow")
-	       << MTagInline("mo", "form='prefix' fence='true' stretchy='true' symmetric='true'")
+	       << MTagInline("mo", attr)
 	       << convertDelimToXMLEscape(left_)
 	       << ETagInline("mo");
 	}
 	ms << cell(0);
 	if (!right_.empty() && ((right_.size() == 1 && right_[0] != ' ') || right_.size() > 1)) {
-	    ms << MTagInline("mo", "form='postfix' fence='true' stretchy='true' symmetric='true'")
+	    ms << MTagInline("mo", attr)
 	       << convertDelimToXMLEscape(right_)
 	       << ETagInline("mo")
 	       << ETag("mrow");