diff --git a/lbr/Protofusion.lbr b/lbr/Protofusion.lbr
--- a/lbr/Protofusion.lbr
+++ b/lbr/Protofusion.lbr
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <!DOCTYPE eagle SYSTEM "eagle.dtd">
-<eagle version="7.2.0">
+<eagle version="7.3.0">
 <drawing>
 <settings>
 <setting alwaysvectorfont="no"/>
@@ -35806,7 +35806,7 @@ MOLEX SMD P/N: 43743-8101</description>
 </device>
 </devices>
 </deviceset>
-<deviceset name="STM32F031G6U6">
+<deviceset name="STM32F031G6U6" prefix="U">
 <gates>
 <gate name="G$1" symbol="STM32F031G6U6" x="0" y="0"/>
 </gates>