diff --git a/PENDING.md b/PENDING.md
index 5bf447c1e8..d81e1ffadd 100644
--- a/PENDING.md
+++ b/PENDING.md
@@ -43,6 +43,7 @@ IMPROVEMENTS
 * Gaia CLI  (`gaiacli`)
 
 * Gaia
+  * [\#3158](https://github.com/cosmos/cosmos-sdk/pull/3158) Validate slashing genesis
 
 * SDK
   * [\#3093](https://github.com/cosmos/cosmos-sdk/issues/3093) Ante handler does no longer read all accounts in one go when processing signatures as signature
diff --git a/cmd/gaia/app/sim_test.go b/cmd/gaia/app/sim_test.go
index 67fa05ac58..e84b334d13 100644
--- a/cmd/gaia/app/sim_test.go
+++ b/cmd/gaia/app/sim_test.go
@@ -97,7 +97,7 @@ func appStateFn(r *rand.Rand, accs []simulation.Account) json.RawMessage {
 	stakeGenesis := stake.GenesisState{
 		Pool: stake.InitialPool(),
 		Params: stake.Params{
-			UnbondingTime: time.Duration(r.Intn(60*60*24*3*2)) * time.Second,
+			UnbondingTime: time.Duration(randIntBetween(r, 60, 60*60*24*3*2)) * time.Second,
 			MaxValidators: uint16(r.Intn(250)),
 			BondDenom:     stakeTypes.DefaultBondDenom,
 		},
@@ -107,9 +107,9 @@ func appStateFn(r *rand.Rand, accs []simulation.Account) json.RawMessage {
 	slashingGenesis := slashing.GenesisState{
 		Params: slashing.Params{
 			MaxEvidenceAge:           stakeGenesis.Params.UnbondingTime,
-			DoubleSignUnbondDuration: time.Duration(r.Intn(60*60*24)) * time.Second,
-			SignedBlocksWindow:       int64(r.Intn(1000)),
-			DowntimeUnbondDuration:   time.Duration(r.Intn(86400)) * time.Second,
+			DoubleSignUnbondDuration: time.Duration(randIntBetween(r, 60, 60*60*24)) * time.Second,
+			SignedBlocksWindow:       int64(randIntBetween(r, 10, 1000)),
+			DowntimeUnbondDuration:   time.Duration(randIntBetween(r, 60, 60*60*24)) * time.Second,
 			MinSignedPerWindow:       sdk.NewDecWithPrec(int64(r.Intn(10)), 1),
 			SlashFractionDoubleSign:  sdk.NewDec(1).Quo(sdk.NewDec(int64(r.Intn(50) + 1))),
 			SlashFractionDowntime:    sdk.NewDec(1).Quo(sdk.NewDec(int64(r.Intn(200) + 1))),
@@ -167,6 +167,10 @@ func appStateFn(r *rand.Rand, accs []simulation.Account) json.RawMessage {
 	return appState
 }
 
+func randIntBetween(r *rand.Rand, min, max int) int {
+	return r.Intn(max-min) + min
+}
+
 func testAndRunTxs(app *GaiaApp) []simulation.WeightedOperation {
 	return []simulation.WeightedOperation{
 		{5, authsim.SimulateDeductFee(app.accountKeeper, app.feeCollectionKeeper)},
diff --git a/x/slashing/genesis.go b/x/slashing/genesis.go
index 05ac917817..fa4abac2f8 100644
--- a/x/slashing/genesis.go
+++ b/x/slashing/genesis.go
@@ -1,6 +1,9 @@
 package slashing
 
 import (
+	"fmt"
+	"time"
+
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	"github.com/cosmos/cosmos-sdk/x/stake/types"
 )
@@ -29,8 +32,43 @@ func DefaultGenesisState() GenesisState {
 	}
 }
 
-// ValidateGenesis TODO https://github.com/cosmos/cosmos-sdk/issues/3008
+// ValidateGenesis validates the slashing genesis parameters
 func ValidateGenesis(data GenesisState) error {
+	downtime := data.Params.SlashFractionDowntime
+	if downtime.IsNegative() || downtime.GT(sdk.OneDec()) {
+		return fmt.Errorf("Slashing fraction downtime should be less than or equal to one and greater than zero, is %s", downtime.String())
+	}
+
+	dblSign := data.Params.SlashFractionDoubleSign
+	if dblSign.IsNegative() || dblSign.GT(sdk.OneDec()) {
+		return fmt.Errorf("Slashing fraction double sign should be less than or equal to one and greater than zero, is %s", dblSign.String())
+	}
+
+	minSign := data.Params.MinSignedPerWindow
+	if minSign.IsNegative() || minSign.GT(sdk.OneDec()) {
+		return fmt.Errorf("Min signed per window should be less than or equal to one and greater than zero, is %s", minSign.String())
+	}
+
+	maxEvidence := data.Params.MaxEvidenceAge
+	if maxEvidence < 1*time.Minute {
+		return fmt.Errorf("Max evidence age must be at least 1 minute, is %s", maxEvidence.String())
+	}
+
+	dblSignUnbond := data.Params.DoubleSignUnbondDuration
+	if dblSignUnbond < 1*time.Minute {
+		return fmt.Errorf("Double sign unblond duration must be at least 1 minute, is %s", dblSignUnbond.String())
+	}
+
+	downtimeUnbond := data.Params.DowntimeUnbondDuration
+	if downtimeUnbond < 1*time.Minute {
+		return fmt.Errorf("Downtime unblond duration must be at least 1 minute, is %s", downtimeUnbond.String())
+	}
+
+	signedWindow := data.Params.SignedBlocksWindow
+	if signedWindow < 10 {
+		return fmt.Errorf("Signed blocks window must be at least 10, is %d", signedWindow)
+	}
+
 	return nil
 }