diff --git a/lotus-soup/compositions/composition.toml b/lotus-soup/compositions/composition.toml
index 812697075..39a72d2d4 100644
--- a/lotus-soup/compositions/composition.toml
+++ b/lotus-soup/compositions/composition.toml
@@ -22,7 +22,7 @@
   clients = "3"
   miners = "2"
   genesis_timestamp_offset = "0"
-  balance = "2000000000"    ## be careful, this is in FIL.
+  balance = "20000000.5"
   sectors = "10"
   random_beacon_type = "mock"
   mining_mode = "natural"
diff --git a/lotus-soup/manifest.toml b/lotus-soup/manifest.toml
index e76b1d396..c2f1a9db9 100644
--- a/lotus-soup/manifest.toml
+++ b/lotus-soup/manifest.toml
@@ -35,7 +35,7 @@ instances = { min = 1, max = 100, default = 5 }
   [testcases.params]
   clients   = { type = "int", default = 1 }
   miners    = { type = "int", default = 1 }
-  balance   = { type = "int", default = 1 }
+  balance   = { type = "float", default = 1 }
   sectors   = { type = "int", default = 1 }
   role      = { type = "string" }
 
@@ -64,7 +64,7 @@ instances = { min = 1, max = 100, default = 5 }
   [testcases.params]
   clients = { type = "int", default = 1 }
   miners = { type = "int", default = 1 }
-  balance = { type = "int", default = 1 }
+  balance = { type = "float", default = 1 }
   sectors = { type = "int", default = 1 }
   role = { type = "string" }
   genesis_timestamp_offset = { type = "int", default = 0 }
@@ -94,7 +94,7 @@ instances = { min = 1, max = 100, default = 5 }
   [testcases.params]
   clients = { type = "int", default = 1 }
   miners = { type = "int", default = 1 }
-  balance = { type = "int", default = 1 }
+  balance = { type = "float", default = 1 }
   sectors = { type = "int", default = 1 }
   role = { type = "string" }
 
@@ -127,7 +127,7 @@ instances = { min = 1, max = 100, default = 5 }
   [testcases.params]
   clients = { type = "int", default = 1 }
   miners = { type = "int", default = 1 }
-  balance = { type = "int", default = 1 }
+  balance = { type = "float", default = 1 }
   sectors = { type = "int", default = 1 }
   role = { type = "string" }
   genesis_timestamp_offset = { type = "int", default = 0 }
diff --git a/lotus-soup/testkit/role_bootstrapper.go b/lotus-soup/testkit/role_bootstrapper.go
index 3049a48ca..39d5dba58 100644
--- a/lotus-soup/testkit/role_bootstrapper.go
+++ b/lotus-soup/testkit/role_bootstrapper.go
@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"context"
 	"fmt"
+	mbig "math/big"
 	"time"
 
 	"github.com/filecoin-project/lotus/build"
@@ -57,11 +58,12 @@ func PrepareBootstrapper(t *TestEnvironment) (*Bootstrapper, error) {
 
 	totalBalance := big.Zero()
 	for _, b := range balances {
-		totalBalance = big.Add(big.NewInt(int64(b.Balance)), totalBalance)
+		totalBalance = big.Add(filToAttoFil(b.Balance), totalBalance)
 	}
 
-	t.RecordMessage("TOTAL BALANCE: %s", totalBalance)
-	if max := types.TotalFilecoinInt; totalBalance.GreaterThanEqual(max) {
+	totalBalanceFil := attoFilToFil(totalBalance)
+	t.RecordMessage("TOTAL BALANCE: %s AttoFIL (%s FIL)", totalBalance, totalBalanceFil)
+	if max := types.TotalFilecoinInt; totalBalanceFil.GreaterThanEqual(max) {
 		panic(fmt.Sprintf("total sum of balances is greater than max Filecoin ever; sum=%s, max=%s", totalBalance, max))
 	}
 
@@ -76,7 +78,7 @@ func PrepareBootstrapper(t *TestEnvironment) (*Bootstrapper, error) {
 	var genesisMiners []genesis.Miner
 
 	for _, bm := range balances {
-		balance := big.Mul(big.NewInt(int64(bm.Balance)), types.NewInt(build.FilecoinPrecision))
+		balance := filToAttoFil(bm.Balance)
 		t.RecordMessage("balance assigned to actor %s: %s AttoFIL", bm.Addr, balance)
 		genesisActors = append(genesisActors,
 			genesis.Actor{
@@ -178,3 +180,18 @@ func (b *Bootstrapper) RunDefault() error {
 	b.t.SyncClient.MustSignalAndWait(ctx, StateDone, b.t.TestInstanceCount)
 	return nil
 }
+
+// filToAttoFil converts a fractional filecoin value into AttoFIL, rounding if necessary
+func filToAttoFil(f float64) big.Int {
+	a := mbig.NewFloat(f)
+	a.Mul(a, mbig.NewFloat(float64(build.FilecoinPrecision)))
+	i, _ := a.Int(nil)
+	return big.Int{Int: i}
+}
+
+func attoFilToFil(atto big.Int) big.Int {
+	i := big.NewInt(0)
+	i.Add(i.Int, atto.Int)
+	i.Div(i.Int, big.NewIntUnsigned(build.FilecoinPrecision).Int)
+	return i
+}
diff --git a/lotus-soup/testkit/role_client.go b/lotus-soup/testkit/role_client.go
index 7c62862b3..08bb82fbb 100644
--- a/lotus-soup/testkit/role_client.go
+++ b/lotus-soup/testkit/role_client.go
@@ -45,7 +45,7 @@ func PrepareClient(t *TestEnvironment) (*LotusClient, error) {
 	}
 
 	// publish the account ID/balance
-	balance := t.IntParam("balance")
+	balance := t.FloatParam("balance")
 	balanceMsg := &InitialBalanceMsg{Addr: walletKey.Address, Balance: balance}
 	t.SyncClient.Publish(ctx, BalanceTopic, balanceMsg)
 
diff --git a/lotus-soup/testkit/role_miner.go b/lotus-soup/testkit/role_miner.go
index 86047dece..4850efedf 100644
--- a/lotus-soup/testkit/role_miner.go
+++ b/lotus-soup/testkit/role_miner.go
@@ -63,7 +63,7 @@ func PrepareMiner(t *TestEnvironment) (*LotusMiner, error) {
 	}
 
 	// publish the account ID/balance
-	balance := t.IntParam("balance")
+	balance := t.FloatParam("balance")
 	balanceMsg := &InitialBalanceMsg{Addr: walletKey.Address, Balance: balance}
 	t.SyncClient.Publish(ctx, BalanceTopic, balanceMsg)
 
diff --git a/lotus-soup/testkit/sync.go b/lotus-soup/testkit/sync.go
index f565c501d..51975ce29 100644
--- a/lotus-soup/testkit/sync.go
+++ b/lotus-soup/testkit/sync.go
@@ -27,7 +27,7 @@ var (
 
 type InitialBalanceMsg struct {
 	Addr    address.Address
-	Balance int
+	Balance float64
 }
 
 type PresealMsg struct {