diff --git a/state/state.go b/state/state.go
index 3a8b98d0..2ebbec10 100644
--- a/state/state.go
+++ b/state/state.go
@@ -266,7 +266,7 @@ func (s *State) GetValidators() (*types.ValidatorSet, *types.ValidatorSet) {
 func (s *State) Params() types.ConsensusParams {
 	// TODO: this should move into the State proper
 	// when we allow the app to change it
-	return s.GenesisDoc.ConsensusParams
+	return *s.GenesisDoc.ConsensusParams
 }
 
 //------------------------------------------------------------------------
diff --git a/types/genesis.go b/types/genesis.go
index e57787c4..f1b2736f 100644
--- a/types/genesis.go
+++ b/types/genesis.go
@@ -26,7 +26,7 @@ type GenesisValidator struct {
 type GenesisDoc struct {
 	GenesisTime     time.Time          `json:"genesis_time"`
 	ChainID         string             `json:"chain_id"`
-	ConsensusParams ConsensusParams    `json:"consensus_params"`
+	ConsensusParams *ConsensusParams   `json:"consensus_params,omitempty"`
 	Validators      []GenesisValidator `json:"validators"`
 	AppHash         data.Bytes         `json:"app_hash"`
 }
@@ -58,8 +58,7 @@ func (genDoc *GenesisDoc) ValidateAndComplete() error {
 		return errors.Errorf("Genesis doc must include non-empty chain_id")
 	}
 
-	var emptyParams ConsensusParams
-	if genDoc.ConsensusParams == emptyParams {
+	if genDoc.ConsensusParams == nil {
 		genDoc.ConsensusParams = DefaultConsensusParams()
 	} else {
 		if err := genDoc.ConsensusParams.Validate(); err != nil {
diff --git a/types/params.go b/types/params.go
index cd324219..495d1fd4 100644
--- a/types/params.go
+++ b/types/params.go
@@ -35,8 +35,8 @@ type BlockGossipParams struct {
 }
 
 // DefaultConsensusParams returns a default ConsensusParams.
-func DefaultConsensusParams() ConsensusParams {
-	return ConsensusParams{
+func DefaultConsensusParams() *ConsensusParams {
+	return &ConsensusParams{
 		DefaultBlockSizeParams(),
 		DefaultTxSizeParams(),
 		DefaultBlockGossipParams(),