diff --git a/modules/juce_core/text/juce_String.h b/modules/juce_core/text/juce_String.h
index b9c9235041..e9c34a9472 100644
--- a/modules/juce_core/text/juce_String.h
+++ b/modules/juce_core/text/juce_String.h
@@ -1335,6 +1335,8 @@ JUCE_API String& JUCE_CALLTYPE operator<< (String& string1, int number);
 /** Appends a decimal number at the end of a string. */
 JUCE_API String& JUCE_CALLTYPE operator<< (String& string1, long number);
 /** Appends a decimal number at the end of a string. */
+JUCE_API String& JUCE_CALLTYPE operator<< (String& string1, unsigned long number);
+/** Appends a decimal number at the end of a string. */
 JUCE_API String& JUCE_CALLTYPE operator<< (String& string1, int64 number);
 /** Appends a decimal number at the end of a string. */
 JUCE_API String& JUCE_CALLTYPE operator<< (String& string1, uint64 number);