Index: binaries/data/mods/public/gui/session/input.js
===================================================================
--- binaries/data/mods/public/gui/session/input.js
+++ binaries/data/mods/public/gui/session/input.js
@@ -46,6 +46,9 @@
 const doubleClickTime = 500;
 var doubleClickTimer = 0;
 var doubleClicked = false;
+var doubleClickDistSquared = 10; // squared number of pixels the mouse may move between clicks of a double click
+var prevXClick = 0;
+var prevYClick = 0;
 // Store the previously clicked entity - ensure a double/triple click happens on the same entity
 var prevClickedEntity = 0;
 
@@ -966,7 +969,12 @@
 			{
 				var ents = [];
 				var selectedEntity = Engine.PickEntityAtPoint(ev.x, ev.y);
-				if (selectedEntity == INVALID_ENTITY)
+				var now = new Date();
+				var isDoubleClick = now.getTime() - doubleClickTimer < doubleClickTime
+					 && ((prevXClick - ev.x)*(prevXClick - ev.x) + (prevYClick - ev.y)*(prevYClick - ev.y) <= doubleClickDistSquared);
+				prevXClick = ev.x;
+				prevYClick = ev.y;
+				if (selectedEntity == INVALID_ENTITY && !isDoubleClick)
 				{
 					if (!Engine.HotkeyIsPressed("selection.add") && !Engine.HotkeyIsPressed("selection.remove"))
 					{
@@ -977,8 +985,6 @@
 					return true;
 				}
 
-				var now = new Date();
-
 				// If camera following and we select different unit, stop
 				if (Engine.GetFollowedEntity() != selectedEntity)
 				{
@@ -985,7 +991,7 @@
 					Engine.CameraFollow(0);
 				}
 
-				if (now.getTime() - doubleClickTimer < doubleClickTime && selectedEntity == prevClickedEntity)
+				if (isDoubleClick)
 				{
 					// Double click or triple click has occurred
 					var showOffscreen = Engine.HotkeyIsPressed("selection.offscreen");
@@ -997,12 +1003,12 @@
 					{
 						// If double click hasn't already occurred, this is a double click.
 						// Select similar units regardless of rank
-						templateToMatch = GetEntityState(selectedEntity).identity.selectionGroupName;
+						templateToMatch = GetEntityState(prevClickedEntity).identity.selectionGroupName;
 						if (templateToMatch)
 							matchRank = false;
 						else
 							// No selection group name defined, so fall back to exact match
-							templateToMatch = GetEntityState(selectedEntity).template;
+							templateToMatch = GetEntityState(prevClickedEntity).template;
 
 						doubleClicked = true;
 						// Reset the timer so the user has an extra period 'doubleClickTimer' to do a triple-click
@@ -1011,7 +1017,7 @@
 					else
 						// Double click has already occurred, so this is a triple click.
 						// Select units matching exact template name (same rank)
-						templateToMatch = GetEntityState(selectedEntity).template;
+						templateToMatch = GetEntityState(prevClickedEntity).template;
 
 					// TODO: Should we handle "control all units" here as well?
 					ents = Engine.PickSimilarPlayerEntities(templateToMatch, showOffscreen, matchRank, false);