diff --git a/mods/ts/rules/gdi-support.yaml b/mods/ts/rules/gdi-support.yaml
index 1cdc42fe42..ab319dd2ba 100644
--- a/mods/ts/rules/gdi-support.yaml
+++ b/mods/ts/rules/gdi-support.yaml
@@ -16,6 +16,8 @@ GAWALL:
 		CrushClasses: heavywall
 	LineBuild:
 		NodeTypes: wall, turret
+	Replaceable:
+		Types: GDIGate, GDITower
 
 GAGATE_A:
 	Inherits: ^Gate_A
@@ -25,6 +27,8 @@ GAGATE_A:
 		Prerequisites: gapile, ~structures.gdi, ~techlevel.low
 	Tooltip:
 		Name: GDI Gate
+	Replacement:
+		ReplaceableTypes: GDIGate
 
 GAGATE_B:
 	Inherits: ^Gate_B
@@ -34,6 +38,8 @@ GAGATE_B:
 		Prerequisites: gapile, ~structures.gdi, ~techlevel.low
 	Tooltip:
 		Name: GDI Gate
+	Replacement:
+		ReplaceableTypes: GDIGate
 
 GACTWR:
 	Inherits: ^Defense
@@ -127,6 +133,8 @@ GACTWR:
 			tower.sam: tower.sam
 	ProvidesPrerequisite@buildingname:
 	SelectionDecorations:
+	Replacement:
+		ReplaceableTypes: GDITower
 
 GAVULC:
 	Inherits: ^BuildingPlug
diff --git a/mods/ts/rules/nod-support.yaml b/mods/ts/rules/nod-support.yaml
index ea2c90f51b..8746a21c97 100644
--- a/mods/ts/rules/nod-support.yaml
+++ b/mods/ts/rules/nod-support.yaml
@@ -16,6 +16,8 @@ NAWALL:
 		CrushClasses: heavywall
 	LineBuild:
 		NodeTypes: wall, turret
+	Replaceable:
+		Types: NodGate
 
 NAGATE_A:
 	Inherits: ^Gate_A
@@ -25,6 +27,8 @@ NAGATE_A:
 		Prerequisites: nahand, ~structures.nod, ~techlevel.low
 	Tooltip:
 		Name: Nod Gate
+	Replacement:
+		ReplaceableTypes: NodGate
 
 NAGATE_B:
 	Inherits: ^Gate_B
@@ -34,6 +38,8 @@ NAGATE_B:
 		Prerequisites: nahand, ~structures.nod, ~techlevel.low
 	Tooltip:
 		Name: Nod Gate
+	Replacement:
+		ReplaceableTypes: NodGate
 
 NAPOST:
 	Inherits: ^Building