diff --git a/binaries/data/mods/public/simulation/components/Foundation.js b/binaries/data/mods/public/simulation/components/Foundation.js
index 044ac087bf..20cd47bdd5 100644
--- a/binaries/data/mods/public/simulation/components/Foundation.js
+++ b/binaries/data/mods/public/simulation/components/Foundation.js
@@ -167,7 +167,7 @@ Foundation.prototype.Build = function(builderEnt, work)
 	var cmpObstruction = Engine.QueryInterface(this.entity, IID_Obstruction);
 	if (cmpObstruction && cmpObstruction.GetBlockMovementFlag())
 	{
-		var collisions = cmpObstruction.GetEntityCollisions(true, true);
+		var collisions = cmpObstruction.GetUnitCollisions();
 		if (collisions.length)
 		{
 			var cmpFoundationOwnership = Engine.QueryInterface(this.entity, IID_Ownership);
diff --git a/binaries/data/mods/public/simulation/components/Gate.js b/binaries/data/mods/public/simulation/components/Gate.js
index 0c1c59caab..c6e62f7b28 100644
--- a/binaries/data/mods/public/simulation/components/Gate.js
+++ b/binaries/data/mods/public/simulation/components/Gate.js
@@ -219,7 +219,7 @@ Gate.prototype.CloseGate = function()
 		return;
 
 	// The gate can't be closed if there are entities colliding with it.
-	var collisions = cmpObstruction.GetEntityCollisions(false, true);
+	var collisions = cmpObstruction.GetUnitCollisions();
 	if (collisions.length)
 	{		
 		if (!this.timer)
diff --git a/source/simulation2/components/CCmpObstruction.cpp b/source/simulation2/components/CCmpObstruction.cpp
index 1bd91664c2..a45b1e4970 100644
--- a/source/simulation2/components/CCmpObstruction.cpp
+++ b/source/simulation2/components/CCmpObstruction.cpp
@@ -597,7 +597,7 @@ public:
 			return !cmpObstructionManager->TestStaticShape(filter, pos.X, pos.Y, cmpPosition->GetRotation().Y, m_Size0, m_Size1, NULL );
 	} 
 
-	virtual std::vector<entity_id_t> GetEntityCollisions(bool checkStructures, bool checkUnits)
+	virtual std::vector<entity_id_t> GetUnitCollisions()
 	{
 		std::vector<entity_id_t> ret;
 
@@ -605,32 +605,15 @@ public:
 		if (!cmpObstructionManager)
 			return ret; // error
 
-		flags_t flags = 0;
-		bool invertMatch = false;
-
 		// There are four 'block' flags: construction, foundation, movement,
 		// and pathfinding. Structures have all of these flags, while units
 		// block only movement and construction.
-
-		// The 'block construction' flag is common to both units and structures.
-		if (checkStructures && checkUnits)
-			flags = ICmpObstructionManager::FLAG_BLOCK_CONSTRUCTION;
-		// The 'block foundation' flag is exclusive to structures.
-		else if (checkStructures)
-			flags = ICmpObstructionManager::FLAG_BLOCK_FOUNDATION;
-		else if (checkUnits)
-		{
-			// As structures block a superset of what units do, matching units
-			// but not structures means excluding entities that contain any of
-			// the structure-specific flags (foundation and pathfinding).
-			invertMatch = true;
-			flags = ICmpObstructionManager::FLAG_BLOCK_FOUNDATION | ICmpObstructionManager::FLAG_BLOCK_PATHFINDING;
-		}
+		flags_t flags = ICmpObstructionManager::FLAG_BLOCK_CONSTRUCTION;
 
 		// Ignore collisions within the same control group, or with other shapes that don't match the filter.
 		// Note that, since the control group for each entity defaults to the entity's ID, this is typically
 		// equivalent to only ignoring the entity's own shape and other shapes that don't match the filter.
-		SkipControlGroupsRequireFlagObstructionFilter filter(invertMatch, m_ControlGroup, m_ControlGroup2, flags);
+		SkipControlGroupsRequireFlagObstructionFilter filter(false, m_ControlGroup, m_ControlGroup2, flags);
 
 		ICmpObstructionManager::ObstructionSquare square;
 		if (!GetObstructionSquare(square))
diff --git a/source/simulation2/components/ICmpObstruction.cpp b/source/simulation2/components/ICmpObstruction.cpp
index 81bcb5d125..3216ae90e4 100644
--- a/source/simulation2/components/ICmpObstruction.cpp
+++ b/source/simulation2/components/ICmpObstruction.cpp
@@ -49,7 +49,7 @@ BEGIN_INTERFACE_WRAPPER(Obstruction)
 DEFINE_INTERFACE_METHOD_0("GetUnitRadius", entity_pos_t, ICmpObstruction, GetUnitRadius)
 DEFINE_INTERFACE_METHOD_2("CheckFoundation", std::string, ICmpObstruction, CheckFoundation_wrapper, std::string, bool)
 DEFINE_INTERFACE_METHOD_0("CheckDuplicateFoundation", bool, ICmpObstruction, CheckDuplicateFoundation)
-DEFINE_INTERFACE_METHOD_2("GetEntityCollisions", std::vector<entity_id_t>, ICmpObstruction, GetEntityCollisions, bool, bool)
+DEFINE_INTERFACE_METHOD_0("GetUnitCollisions", std::vector<entity_id_t>, ICmpObstruction, GetUnitCollisions)
 DEFINE_INTERFACE_METHOD_1("SetActive", void, ICmpObstruction, SetActive, bool)
 DEFINE_INTERFACE_METHOD_3("SetDisableBlockMovementPathfinding", void, ICmpObstruction, SetDisableBlockMovementPathfinding, bool, bool, int32_t)
 DEFINE_INTERFACE_METHOD_0("GetBlockMovementFlag", bool, ICmpObstruction, GetBlockMovementFlag)
diff --git a/source/simulation2/components/ICmpObstruction.h b/source/simulation2/components/ICmpObstruction.h
index 9f3b8e592e..a3375021c2 100644
--- a/source/simulation2/components/ICmpObstruction.h
+++ b/source/simulation2/components/ICmpObstruction.h
@@ -84,11 +84,10 @@ public:
 	virtual bool CheckDuplicateFoundation() = 0;
 
 	/**
-	 * Returns a list of entities that are colliding with this entity,
-	 * filtered depending on type of entities that are requested.
-	 * @return vector of blocking entities
+	 * Returns a list of units that are colliding with this entity,
+	 * @return vector of blocking units
 	 */
-	virtual std::vector<entity_id_t> GetEntityCollisions(bool checkStructures, bool checkUnits) = 0;
+	virtual std::vector<entity_id_t> GetUnitCollisions() = 0;
 
 	/**
 	 * Detects collisions between foundation-blocking entities and