Index: binaries/data/mods/public/simulation/components/Formation.js
===================================================================
--- binaries/data/mods/public/simulation/components/Formation.js
+++ binaries/data/mods/public/simulation/components/Formation.js
@@ -892,7 +892,7 @@
 
 Formation.prototype.AreAnglesSimilar = function(a1, a2)
 {
-	const d = Math.abs(a1 - a2) % 2 * Math.PI;
+	const d = Math.abs(a1 - a2) % (2 * Math.PI);
 	return d < this.maxTurningAngle || d > 2 * Math.PI - this.maxTurningAngle;
 };
 
Index: binaries/data/mods/public/simulation/components/tests/test_Formation.js
===================================================================
--- binaries/data/mods/public/simulation/components/tests/test_Formation.js
+++ binaries/data/mods/public/simulation/components/tests/test_Formation.js
@@ -0,0 +1,32 @@
+Engine.LoadComponentScript("interfaces/Formation.js");
+Engine.LoadComponentScript("Formation.js");
+
+const entity_id = 5;
+
+const formation_template = {
+	"maxTurningAngle": Math.PI/2
+};
+
+function setEntityUp()
+{
+	let cmpFormation = ConstructComponent(entity_id, "Formation", formation_template);
+	return cmpFormation;
+}
+
+var cmpFormation = setEntityUp();
+
+let angle1 = Math.PI/2;
+let angle2 = - angle1;
+TS_ASSERT_EQUALS(cmpFormation.AreAnglesSimilar(angle1, angle2), false);
+
+angle1 = Math.PI/5;
+angle2 = - angle1;
+TS_ASSERT_EQUALS(cmpFormation.AreAnglesSimilar(angle1, angle2), true);
+
+angle1 = 10 * Math.PI/2;
+angle2 = - angle1;
+TS_ASSERT_EQUALS(cmpFormation.AreAnglesSimilar(angle1, angle2), false);
+
+angle1 = 10 * Math.PI/5;
+angle2 = - angle1;
+TS_ASSERT_EQUALS(cmpFormation.AreAnglesSimilar(angle1, angle2), true);