diff --git a/src/mathed/InsetMathDelim.cpp b/src/mathed/InsetMathDelim.cpp
index 78d26fceea..d32029b818 100644
--- a/src/mathed/InsetMathDelim.cpp
+++ b/src/mathed/InsetMathDelim.cpp
@@ -189,15 +189,20 @@ void InsetMathDelim::mathematica(MathematicaStream & os) const
 
 void InsetMathDelim::mathmlize(MathMLStream & ms) const
 {
-	ms << MTag("mrow")
-	   << MTagInline("mo", "form='prefix' fence='true' stretchy='true' symmetric='true'")
-	   << convertDelimToXMLEscape(left_)
-	   << ETagInline("mo")
-	   << cell(0)
-	   << MTagInline("mo", "form='postfix' fence='true' stretchy='true' symmetric='true'")
-	   << convertDelimToXMLEscape(right_)
-	   << ETagInline("mo")
-	   << ETag("mrow");
+	// Ignore the delimiter if: it is empty or only a space (one character).
+	if (!left_.empty() && ((left_.size() == 1 && left_[0] != ' ') || left_.size() > 1)) {
+	    ms << MTag("mrow")
+	       << MTagInline("mo", "form='prefix' fence='true' stretchy='true' symmetric='true'")
+	       << 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'")
+	       << convertDelimToXMLEscape(right_)
+	       << ETagInline("mo")
+	       << ETag("mrow");
+	}
 }
 
 
diff --git a/src/mathed/InsetMathFrac.cpp b/src/mathed/InsetMathFrac.cpp
index f6f2f95b0a..b0ff55bc4d 100644
--- a/src/mathed/InsetMathFrac.cpp
+++ b/src/mathed/InsetMathFrac.cpp
@@ -768,15 +768,20 @@ void InsetMathBinom::mathmlize(MathMLStream & ms) const
 		rdelim = ']';
 		break;
 	}
-	ms << MTagInline("mo", "fence='true' stretchy='true' form='prefix'")
-	   << ldelim
-	   << ETagInline("mo")
-	   << MTagInline("mfrac", "linethickness='0'")
+
+	if (ldelim != ' ') {
+	    ms << MTagInline("mo", "fence='true' stretchy='true' form='prefix'")
+	       << ldelim
+	       << ETagInline("mo");
+	}
+	ms << MTagInline("mfrac", "linethickness='0'")
 	   << cell(0) << cell(1)
-       << ETagInline("mfrac")
-	   << MTagInline("mo", "fence='true' stretchy='true' form='postfix'")
-	   << rdelim
-	   << ETagInline("mo");
+	   << ETagInline("mfrac");
+	if (rdelim != ' ') {
+	    ms << MTagInline("mo", "fence='true' stretchy='true' form='postfix'")
+	       << rdelim
+	       << ETagInline("mo");
+	}
 }