diff --git a/swing/src/net/sf/openrocket/gui/configdialog/ComponentAssemblyConfig.java b/swing/src/net/sf/openrocket/gui/configdialog/ComponentAssemblyConfig.java
index f6554f544..b4aebd2be 100644
--- a/swing/src/net/sf/openrocket/gui/configdialog/ComponentAssemblyConfig.java
+++ b/swing/src/net/sf/openrocket/gui/configdialog/ComponentAssemblyConfig.java
@@ -86,7 +86,7 @@ public class ComponentAssemblyConfig extends RocketComponentConfig {
 		// set angle
 		JLabel angleLabel = new JLabel(trans.get("StageConfig.parallel.angle"));
 		motherPanel.add( angleLabel, "align left");
-		DoubleModel angleModel = new DoubleModel( boosters, "AngleOffset", 1.0, UnitGroup.UNITS_ANGLE, 0.0, Math.PI*2);
+		DoubleModel angleModel = new DoubleModel( boosters, "AngleOffset", 1.0, UnitGroup.UNITS_ANGLE, -Math.PI, Math.PI);
 
 		JSpinner angleSpinner = new JSpinner(angleModel.getSpinnerModel());
 		angleSpinner.setEditor(new SpinnerEditor(angleSpinner));