diff --git a/lib/babe/build.go b/lib/babe/build.go
index 4b2f373632..ea3e1e2785 100644
--- a/lib/babe/build.go
+++ b/lib/babe/build.go
@@ -34,7 +34,7 @@ import (
 
 // construct a block for this slot with the given parent
 func (b *Service) buildBlock(parent *types.Header, slot Slot) (*types.Block, error) {
-	builder, err := NewBuilder(
+	builder, err := NewBlockBuilder(
 		b.rt,
 		b.keypair,
 		b.transactionState,
diff --git a/lib/babe/build_test.go b/lib/babe/build_test.go
index 8f80858976..5da12b3cf4 100644
--- a/lib/babe/build_test.go
+++ b/lib/babe/build_test.go
@@ -45,7 +45,7 @@ func TestSeal(t *testing.T) {
 
 	babeService := createTestService(t, cfg)
 
-	builder, _ := NewBuilder(
+	builder, _ := NewBlockBuilder(
 		babeService.rt,
 		babeService.keypair,
 		babeService.transactionState,
@@ -124,7 +124,7 @@ func TestBuildBlock_ok(t *testing.T) {
 	babeService := createTestService(t, cfg)
 	babeService.epochData.threshold = maxThreshold
 
-	builder, _ := NewBuilder(
+	builder, _ := NewBlockBuilder(
 		babeService.rt,
 		babeService.keypair,
 		babeService.transactionState,
diff --git a/lib/babe/median_test.go b/lib/babe/median_test.go
index 9fedb8b19c..dca0040eb8 100644
--- a/lib/babe/median_test.go
+++ b/lib/babe/median_test.go
@@ -67,7 +67,7 @@ func addBlocksToState(t *testing.T, babeService *Service, depth int, blockState
 	previousHash := blockState.BestBlockHash()
 	previousAT := startTime
 	duration, err := time.ParseDuration("1s")
-	builder, _ := NewBuilder(
+	builder, _ := NewBlockBuilder(
 		babeService.rt,
 		babeService.keypair,
 		babeService.transactionState,
@@ -139,7 +139,7 @@ func TestEstimateCurrentSlot(t *testing.T) {
 	babeService.epochData.threshold = maxThreshold
 	babeService.epochData.authorityIndex = 0
 
-	builder, _ := NewBuilder(
+	builder, _ := NewBlockBuilder(
 		babeService.rt,
 		babeService.keypair,
 		babeService.transactionState,
diff --git a/lib/babe/verify_test.go b/lib/babe/verify_test.go
index 27feffb58d..335208159b 100644
--- a/lib/babe/verify_test.go
+++ b/lib/babe/verify_test.go
@@ -303,7 +303,7 @@ func TestVerifyPimarySlotWinner(t *testing.T) {
 	babeService.epochData.threshold = maxThreshold
 	babeService.epochData.authorityIndex = 0
 
-	builder, _ := NewBuilder(
+	builder, _ := NewBlockBuilder(
 		babeService.rt,
 		babeService.keypair,
 		babeService.transactionState,