diff --git a/go/consensus/tendermint/abci/mux.go b/go/consensus/tendermint/abci/mux.go
index 71a2c77d9a5..d249c7b6a48 100644
--- a/go/consensus/tendermint/abci/mux.go
+++ b/go/consensus/tendermint/abci/mux.go
@@ -67,6 +67,9 @@ type ApplicationConfig struct {
 
 	// OwnTxSigner is the transaction signer identity of the local node.
 	OwnTxSigner signature.PublicKey
+
+	// TestingMemDB forces the MemDB to be used for the state storage.
+	TestingMemDB bool
 }
 
 // TransactionAuthHandler is the interface for ABCI applications that handle
diff --git a/go/consensus/tendermint/abci/state.go b/go/consensus/tendermint/abci/state.go
index 6738714201c..858f8d23a92 100644
--- a/go/consensus/tendermint/abci/state.go
+++ b/go/consensus/tendermint/abci/state.go
@@ -429,8 +429,15 @@ func (s *applicationState) metricsWorker() {
 	}
 }
 
+func newStateDB(cfg *ApplicationConfig) (dbm.DB, error) {
+	if cfg.TestingMemDB {
+		return dbm.NewMemDB(), nil
+	}
+	return db.New(filepath.Join(cfg.DataDir, "abci-mux-state"), false)
+}
+
 func newApplicationState(ctx context.Context, cfg *ApplicationConfig) (*applicationState, error) {
-	db, err := db.New(filepath.Join(cfg.DataDir, "abci-mux-state"), false)
+	db, err := newStateDB(cfg)
 	if err != nil {
 		return nil, err
 	}
diff --git a/go/oasis-node/cmd/debug/consim/consim.go b/go/oasis-node/cmd/debug/consim/consim.go
index eee7f476520..f7c095ab51b 100644
--- a/go/oasis-node/cmd/debug/consim/consim.go
+++ b/go/oasis-node/cmd/debug/consim/consim.go
@@ -29,6 +29,7 @@ import (
 
 const (
 	cfgNumKept      = "consim.num_kept"
+	cfgMemDB        = "consim.memdb"
 	cfgWorkload     = "consim.workload"
 	cfgWorkloadSeed = "consim.workload.seed"
 )
@@ -115,6 +116,7 @@ func doRun(cmd *cobra.Command, args []string) error {
 		tmChainID:     tmChainID,
 		txAuthHandler: txAuthApp.(abci.TransactionAuthHandler),
 		numVersions:   viper.GetInt64(cfgNumKept),
+		memDB:         viper.GetBool(cfgMemDB),
 	}
 	mockChain, err := initMockChain(ctx, cfg)
 	if err != nil {
@@ -248,6 +250,7 @@ func Register(parentCmd *cobra.Command) {
 
 func init() {
 	flagsConsim.Int64(cfgNumKept, 0, "number of versions kept (0 = all)")
+	flagsConsim.Bool(cfgMemDB, false, "use memory to store state")
 	flagsConsim.String(cfgWorkload, fileWorkloadName, "workload to execute")
 	flagsConsim.String(cfgWorkloadSeed, "seeeeeeeeeeeeeeeeeeeeeeeeeeeeeed", "DRBG seed for workloads")
 	_ = viper.BindPFlags(flagsConsim)
diff --git a/go/oasis-node/cmd/debug/consim/mockchain.go b/go/oasis-node/cmd/debug/consim/mockchain.go
index cabfe3b474a..8fa86cbfbd0 100644
--- a/go/oasis-node/cmd/debug/consim/mockchain.go
+++ b/go/oasis-node/cmd/debug/consim/mockchain.go
@@ -26,6 +26,7 @@ type mockChainCfg struct {
 	tmChainID     string
 	txAuthHandler abci.TransactionAuthHandler
 	numVersions   int64
+	memDB         bool
 }
 
 type mockChain struct {
@@ -158,6 +159,7 @@ func initMockChain(ctx context.Context, cfg *mockChainCfg) (*mockChain, error) {
 		HaltEpochHeight: math.MaxUint64,
 		MinGasPrice:     0, // XXX: Should this be configurable?
 		OwnTxSigner:     localSigner.Public(),
+		TestingMemDB:    cfg.memDB,
 	}
 	if cfg.numVersions > 0 {
 		muxCfg.Pruning.Strategy = abci.PruneKeepN