diff --git a/core/src/net/sf/openrocket/unit/UnitGroup.java b/core/src/net/sf/openrocket/unit/UnitGroup.java
index 301fe2c08..67140bad1 100644
--- a/core/src/net/sf/openrocket/unit/UnitGroup.java
+++ b/core/src/net/sf/openrocket/unit/UnitGroup.java
@@ -85,7 +85,7 @@ public class UnitGroup {
 		UNITS_LENGTH.addUnit(new GeneralUnit(0.01, "cm"));
 		UNITS_LENGTH.addUnit(new GeneralUnit(1, "m"));
 		UNITS_LENGTH.addUnit(new GeneralUnit(0.0254, "in"));
-		UNITS_LENGTH.addUnit(new FractionalUnit(0.0254, "in/64", "in", 64, 1d/16d));
+		UNITS_LENGTH.addUnit(new FractionalUnit(0.0254, "in/64", "in", 64, 1d/16d, 0.5d/64d));
 		UNITS_LENGTH.addUnit(new GeneralUnit(0.3048, "ft"));
 		UNITS_LENGTH.setDefaultUnit(1);