diff --git a/beacon-chain/forkchoice/doubly-linked-tree/proposer_boost_test.go b/beacon-chain/forkchoice/doubly-linked-tree/proposer_boost_test.go
index c132f227155b..5eb001ae9d78 100644
--- a/beacon-chain/forkchoice/doubly-linked-tree/proposer_boost_test.go
+++ b/beacon-chain/forkchoice/doubly-linked-tree/proposer_boost_test.go
@@ -49,6 +49,7 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 		slot := primitives.Slot(1)
 		driftGenesisTime(f, slot, 0)
 		newRoot := indexToHash(1)
+		f.store.proposerBoostRoot = [32]byte{}
 		state, blkRoot, err := prepareForkchoiceState(
 			ctx,
 			slot,
@@ -74,6 +75,7 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 		slot = primitives.Slot(2)
 		driftGenesisTime(f, slot, 0)
 		newRoot = indexToHash(2)
+		f.store.proposerBoostRoot = [32]byte{}
 		state, blkRoot, err = prepareForkchoiceState(
 			ctx,
 			slot,
@@ -101,6 +103,7 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 		slot = primitives.Slot(3)
 		driftGenesisTime(f, slot, 0)
 		newRoot = indexToHash(3)
+		f.store.proposerBoostRoot = [32]byte{}
 		state, blkRoot, err = prepareForkchoiceState(
 			ctx,
 			slot,
@@ -129,6 +132,7 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 		slot = primitives.Slot(4)
 		driftGenesisTime(f, slot, 0)
 		newRoot = indexToHash(4)
+		f.store.proposerBoostRoot = [32]byte{}
 		state, blkRoot, err = prepareForkchoiceState(
 			ctx,
 			slot,
@@ -335,6 +339,7 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 		cSlot := primitives.Slot(2)
 		driftGenesisTime(f, cSlot, 0)
 		c := indexToHash(2)
+		f.store.proposerBoostRoot = [32]byte{}
 		state, blkRoot, err := prepareForkchoiceState(
 			ctx,
 			cSlot,
@@ -354,6 +359,7 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 
 		bSlot := primitives.Slot(1)
 		b := indexToHash(1)
+		f.store.proposerBoostRoot = [32]byte{}
 		state, blkRoot, err = prepareForkchoiceState(
 			ctx,
 			bSlot,
@@ -378,6 +384,7 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 		// A block D, building on B, is received at slot N+3. It should not be able to win without boosting.
 		dSlot := primitives.Slot(3)
 		d := indexToHash(3)
+		f.store.proposerBoostRoot = [32]byte{}
 		state, blkRoot, err = prepareForkchoiceState(
 			ctx,
 			dSlot,
@@ -398,6 +405,7 @@ func TestForkChoice_BoostProposerRoot_PreventsExAnteAttack(t *testing.T) {
 		// If the same block arrives with boosting then it becomes head:
 		driftGenesisTime(f, dSlot, 0)
 		d2 := indexToHash(30)
+		f.store.proposerBoostRoot = [32]byte{}
 		state, blkRoot, err = prepareForkchoiceState(
 			ctx,
 			dSlot,
diff --git a/beacon-chain/forkchoice/doubly-linked-tree/store.go b/beacon-chain/forkchoice/doubly-linked-tree/store.go
index dbf89590f375..1fbb28076637 100644
--- a/beacon-chain/forkchoice/doubly-linked-tree/store.go
+++ b/beacon-chain/forkchoice/doubly-linked-tree/store.go
@@ -109,7 +109,8 @@ func (s *Store) insert(ctx context.Context,
 		secondsIntoSlot := (timeNow - s.genesisTime) % params.BeaconConfig().SecondsPerSlot
 		currentSlot := slots.CurrentSlot(s.genesisTime)
 		boostThreshold := params.BeaconConfig().SecondsPerSlot / params.BeaconConfig().IntervalsPerSlot
-		if currentSlot == slot && secondsIntoSlot < boostThreshold {
+		isFirstBlock := s.proposerBoostRoot == [32]byte{}
+		if currentSlot == slot && secondsIntoSlot < boostThreshold && isFirstBlock {
 			s.proposerBoostRoot = root
 		}