diff --git a/x/mock/simulation/event_stats.go b/x/mock/simulation/event_stats.go
index 5276c533b..f54eef4cc 100644
--- a/x/mock/simulation/event_stats.go
+++ b/x/mock/simulation/event_stats.go
@@ -10,12 +10,9 @@ type eventStats map[string]uint
 func newEventStats() eventStats {
 	events := make(map[string]uint)
 	return events
-	event := func(what string) {
-		events[what]++
-	}
 }
 
-func (es *eventStats) tally(eventDesc string) {
+func (es eventStats) tally(eventDesc string) {
 	es[eventDesc]++
 }
 
diff --git a/x/mock/simulation/mock_tendermint.go b/x/mock/simulation/mock_tendermint.go
index a98e89614..2ddac2e79 100644
--- a/x/mock/simulation/mock_tendermint.go
+++ b/x/mock/simulation/mock_tendermint.go
@@ -20,9 +20,10 @@ type mockValidator struct {
 type mockValidators map[string]mockValidator
 
 // get mockValidators from abci validators
-func newMockValidators(abciVals abci.ValidatorUpdate) mockValidators {
+func newMockValidators(r *rand.Rand, abciVals []abci.ValidatorUpdate,
+	params Params) mockValidators {
 
-	validators = make(mockValidators)
+	validators := make(mockValidators)
 	for _, validator := range abciVals {
 		str := fmt.Sprintf("%v", validator.PubKey)
 		liveliness := GetMemberOfInitialState(r,
@@ -39,9 +40,9 @@ func newMockValidators(abciVals abci.ValidatorUpdate) mockValidators {
 
 // TODO describe usage
 func (vals mockValidators) getKeys() []string {
-	keys := make([]string, len(validators))
+	keys := make([]string, len(vals))
 	i := 0
-	for key := range validators {
+	for key := range vals {
 		keys[i] = key
 		i++
 	}
@@ -52,13 +53,13 @@ func (vals mockValidators) getKeys() []string {
 //_________________________________________________________________________________
 
 // randomProposer picks a random proposer from the current validator set
-func randomProposer(r *rand.Rand, validators map[string]mockValidator) cmn.HexBytes {
-	keys := validators.getKeys()
+func (vals mockValidators) randomProposer(r *rand.Rand) cmn.HexBytes {
+	keys := vals.getKeys()
 	if len(keys) == 0 {
 		return nil
 	}
 	key := keys[r.Intn(len(keys))]
-	proposer := validators[key].val
+	proposer := vals[key].val
 	pk, err := tmtypes.PB2TM.PubKey(proposer.PubKey)
 	if err != nil {
 		panic(err)
diff --git a/x/mock/simulation/operation.go b/x/mock/simulation/operation.go
index 7710cf5c9..00237e03e 100644
--- a/x/mock/simulation/operation.go
+++ b/x/mock/simulation/operation.go
@@ -86,17 +86,17 @@ type WeightedOperation struct {
 // WeightedOperations is the group of all weighted operations to simulate.
 type WeightedOperations []WeightedOperation
 
-func (w WeightedOperations) totalWeight() int {
+func (ops WeightedOperations) totalWeight() int {
 	totalOpWeight := 0
-	for i := 0; i < len(w); i++ {
-		totalOpWeight += w[i].Weight
+	for _, op := range ops {
+		totalOpWeight += op.Weight
 	}
 	return totalOpWeight
 }
 
 type selectOpFn func(r *rand.Rand) Operation
 
-func (w WeightedOperations) getSelectOpFn() selectOpFn {
+func (ops WeightedOperations) getSelectOpFn() selectOpFn {
 	totalOpWeight := ops.totalWeight()
 	return func(r *rand.Rand) Operation {
 		x := r.Intn(totalOpWeight)
diff --git a/x/mock/simulation/simulate.go b/x/mock/simulation/simulate.go
index e6749f4e1..ac0e5d3f7 100644
--- a/x/mock/simulation/simulate.go
+++ b/x/mock/simulation/simulate.go
@@ -43,7 +43,7 @@ func initChain(r *rand.Rand, params Params, accounts []Account,
 		AppStateBytes: appStateFn(r, accounts),
 	}
 	res := app.InitChain(req)
-	validators = newMockValidators(res.Validators)
+	validators := newMockValidators(r, res.Validators, params)
 
 	for i := 0; i < len(setups); i++ {
 		setups[i](r, accounts)
@@ -76,16 +76,16 @@ func SimulateFromSeed(tb testing.TB, app *baseapp.BaseApp,
 	timeDiff := maxTimePerBlock - minTimePerBlock
 	accs := RandomAccounts(r, params.NumKeys)
 	eventStats := newEventStats()
-	validators := initChain(r, params, accs, setups, app, appStateFn)
 
 	// Second variable to keep pending validator set (delayed one block since
 	// TM 0.24) Initially this is the same as the initial validator set
-	nextValidators := validators()
+	validators := initChain(r, params, accs, setups, app, appStateFn)
+	nextValidators := validators
 
 	header := abci.Header{
 		Height:          1,
 		Time:            timestamp,
-		ProposerAddress: randomProposer(r, validators),
+		ProposerAddress: validators.randomProposer(r),
 	}
 	opCount := 0
 
@@ -186,7 +186,7 @@ func SimulateFromSeed(tb testing.TB, app *baseapp.BaseApp,
 			time.Duration(minTimePerBlock) * time.Second)
 		header.Time = header.Time.Add(
 			time.Duration(int64(r.Intn(int(timeDiff)))) * time.Second)
-		header.ProposerAddress = randomProposer(r, validators)
+		header.ProposerAddress = validators.randomProposer(r)
 		logWriter("EndBlock")
 
 		if testingMode {