diff --git a/ArduinoLog.cpp b/ArduinoLog.cpp
index 4dba1aa..b66aa8b 100644
--- a/ArduinoLog.cpp
+++ b/ArduinoLog.cpp
@@ -169,6 +169,10 @@ void Logging::printFormat(const char format, va_list *args) {
 	{
 		_logOutput->print(va_arg(*args, long), DEC);
 	}
+	else if (format == 'u')
+	{
+		_logOutput->print(va_arg(*args, unsigned long), DEC);
+	}
 	else if (format == 'c')
 	{
 		_logOutput->print((char) va_arg(*args, int));
diff --git a/README.md b/README.md
index cd0bb23..bf2ffaf 100644
--- a/README.md
+++ b/README.md
@@ -103,6 +103,7 @@ where the format string can be used to format the log variables
 * %c	display as single character
 * %d	display as integer value
 * %l	display as long value
+* %u	display as unsigned long value
 * %x	display as hexadecimal value
 * %X	display as hexadecimal value prefixed by `0x`
 * %b	display as  binary number