diff --git a/src/game/engine/tests/integration/test_happiness_turn.gd b/src/game/engine/tests/integration/test_happiness_turn.gd
index e78bfffa..752328ab 100644
--- a/src/game/engine/tests/integration/test_happiness_turn.gd
+++ b/src/game/engine/tests/integration/test_happiness_turn.gd
@@ -40,6 +40,10 @@ func _make_player(growth_tier: String = "balanced") -> RefCounted:
 
 func _make_city(population: int, buildings: Array[String]) -> RefCounted:
 	var city: RefCounted = CityScript.new("test_city_%d" % randi(), [] as Array[String])
+	# owner drives _pi (the parallel-city-slot player row); without it _pi stays
+	# -1 and found()/set_population address an invalid row, so population never
+	# leaves the default 1 — which silently broke every happiness assertion.
+	city.owner = 0
 	city.found("Testhold", 5, 5, true, 1)
 	city.set_population(population)
 	for bld: String in buildings: