diff --git a/modules/juce_core/xml/juce_XmlElement.cpp b/modules/juce_core/xml/juce_XmlElement.cpp
index 28787d9afc..eb06df3f7b 100644
--- a/modules/juce_core/xml/juce_XmlElement.cpp
+++ b/modules/juce_core/xml/juce_XmlElement.cpp
@@ -528,7 +528,7 @@ void XmlElement::setAttribute (const String& attributeName, const int number)
 
 void XmlElement::setAttribute (const String& attributeName, const double number)
 {
-    setAttribute (attributeName, String (number));
+    setAttribute (attributeName, String (number, 20));
 }
 
 void XmlElement::removeAttribute (const String& attributeName) noexcept