diff --git a/cmd/blockimporter/block_source.go b/cmd/blockimporter/block_source.go
index b41e98c3590..790d6036273 100644
--- a/cmd/blockimporter/block_source.go
+++ b/cmd/blockimporter/block_source.go
@@ -341,3 +341,31 @@ func (decorator *retryBlockSourceDecorator) GetChainID() (int64, error) {
 
 	return 0, err
 }
+
+type secondaryBlocksSourceDecorator struct {
+	primarySource         BlockSource
+	secondaryBlocksSource BlockSource
+}
+
+func WithSecondaryBlocksSource(primarySource BlockSource, secondaryBlocksSource BlockSource) BlockSource {
+	return &secondaryBlocksSourceDecorator{
+		primarySource:         primarySource,
+		secondaryBlocksSource: secondaryBlocksSource,
+	}
+}
+
+func (decorator *secondaryBlocksSourceDecorator) PollBlocks(fromBlock uint64) ([]types.Block, error) {
+	if blocks, err := decorator.primarySource.PollBlocks(fromBlock); err == nil {
+		return blocks, err
+	}
+
+	return decorator.secondaryBlocksSource.PollBlocks(fromBlock)
+}
+
+func (decorator *secondaryBlocksSourceDecorator) GetInitialBalances() ([]BalanceEntry, error) {
+	return decorator.primarySource.GetInitialBalances()
+}
+
+func (decorator *secondaryBlocksSourceDecorator) GetChainID() (int64, error) {
+	return decorator.primarySource.GetChainID()
+}
diff --git a/cmd/blockimporter/import_runner.go b/cmd/blockimporter/import_runner.go
index 440a3d082a3..fee866aabaa 100644
--- a/cmd/blockimporter/import_runner.go
+++ b/cmd/blockimporter/import_runner.go
@@ -16,7 +16,7 @@ type Settings struct {
 	PollInterval  time.Duration
 }
 
-func RunImport(settings *Settings, blockSource BlockSource) error {
+func RunImport(settings *Settings, blockSource BlockSource, secondaryBlocksSource BlockSource) error {
 	db, err := NewDB(settings.DBPath, settings.Logger)
 	if err != nil {
 		return err
@@ -39,7 +39,7 @@ func RunImport(settings *Settings, blockSource BlockSource) error {
 	}
 
 	blockNum := state.BlockNum()
-	blockSource = makeBlockSource(settings, blockSource)
+	blockSource = makeBlockSource(settings, blockSource, secondaryBlocksSource)
 	for {
 		select {
 		case <-settings.Terminated:
@@ -66,7 +66,16 @@ func RunImport(settings *Settings, blockSource BlockSource) error {
 	}
 }
 
-func makeBlockSource(settings *Settings, blockSource BlockSource) BlockSource {
+func makeBlockSource(settings *Settings, blockSource BlockSource, secondaryBlockSource BlockSource) BlockSource {
+	primarySource := makeSingleBlockSource(settings, blockSource)
+	if secondaryBlockSource != nil {
+		return WithSecondaryBlocksSource(primarySource, makeSingleBlockSource(settings, secondaryBlockSource))
+	} else {
+		return primarySource
+	}
+}
+
+func makeSingleBlockSource(settings *Settings, blockSource BlockSource) BlockSource {
 	if settings.RetryCount > 0 {
 		blockSource = WithRetries(blockSource, settings.RetryCount, settings.RetryInterval, settings.Terminated)
 	}
diff --git a/cmd/blockimporter/import_runner_test.go b/cmd/blockimporter/import_runner_test.go
index ff5bcafcb67..80308fd767e 100644
--- a/cmd/blockimporter/import_runner_test.go
+++ b/cmd/blockimporter/import_runner_test.go
@@ -86,6 +86,6 @@ func TestImport(t *testing.T) {
 		time.Sleep(time.Second)
 		close(settings.Terminated)
 	}()
-	err := RunImport(&settings, NewFileBasedMockBlockSource())
+	err := RunImport(&settings, NewFileBasedMockBlockSource(), nil)
 	require.Empty(t, err)
 }
diff --git a/cmd/blockimporter/main.go b/cmd/blockimporter/main.go
index 2905cfe84f9..0288e572bc8 100644
--- a/cmd/blockimporter/main.go
+++ b/cmd/blockimporter/main.go
@@ -13,8 +13,9 @@ import (
 func main() {
 	// Parse commandline arguments
 	var (
-		dbPath = flag.String("db", "./db", "database path")
-		evmUrl = flag.String("evm", "http://127.0.0.1:8545", "EVM canister HTTP endpoint URL")
+		dbPath                  = flag.String("db", "./db", "database path")
+		evmUrl                  = flag.String("evm", "http://127.0.0.1:8545", "EVM canister HTTP endpoint URL")
+		secondaryBlockSourceUrl = flag.String("secondary-blocks-url", "", "URL of the secondary blocks source")
 	)
 	flag.Parse()
 
@@ -36,7 +37,12 @@ func main() {
 	}()
 
 	blockSource := NewHttpBlockSource(*evmUrl)
-	err := RunImport(&settings, &blockSource)
+	var secondaryBlockSource BlockSource
+	if *secondaryBlockSourceUrl != "" {
+		secondarySource := NewHttpBlockSource(*secondaryBlockSourceUrl)
+		secondaryBlockSource = &secondarySource
+	}
+	err := RunImport(&settings, &blockSource, secondaryBlockSource)
 
 	if err != nil {
 		logger.Error(err.Error())