diff --git a/db_test.go b/db_test.go
index 23d5c41..917eb12 100644
--- a/db_test.go
+++ b/db_test.go
@@ -104,6 +104,30 @@ func TestQueryFitsDroneFilterHasCooccurringModules(t *testing.T) {
 	assert.InDelta(t, 100.0, mod.Percentage, 0.01)
 }
 
+func TestQueryFitsModuleFilterKeepsOtherModulesAndSlots(t *testing.T) {
+	dbi, err := GetDB()
+	require.NoError(t, err)
+	db := dbi.(*DBWrapper)
+
+	resetModuleSlotCache(t)
+
+	shipID := int64(32872)
+	moduleID := int64(16433)
+
+	stats, err := db.QueryFits(QueryParams{Ship: shipID, Modules: []int64{moduleID}})
+	require.NoError(t, err)
+	require.Greater(t, stats.TotalKillmails, int64(0))
+
+	mod := moduleStatsFor(stats, moduleID)
+	require.NotNil(t, mod)
+	assert.Equal(t, stats.TotalKillmails, mod.Count)
+	assert.InDelta(t, 100.0, mod.Percentage, 0.01)
+
+	assert.Greater(t, len(stats.HighSlotModules), 1, "other high-slot modules should remain")
+	otherSlots := len(stats.MidSlotModules) + len(stats.LowSlotModules) + len(stats.Rigs) + len(stats.Drones)
+	assert.Greater(t, otherSlots, 0, "other slot categories should remain populated")
+}
+
 func pickTopSystemID(stats *FitStatistics) int64 {
 	var bestID int64
 	var bestCount int64