diff --git a/tsdb/db.go b/tsdb/db.go
index f63437fc6..dc94806df 100644
--- a/tsdb/db.go
+++ b/tsdb/db.go
@@ -805,6 +805,7 @@ func (db *DB) Compact() (returnErr error) {
 		).Err()
 	}()
 
+	start := time.Now()
 	// Check whether we have pending head blocks that are ready to be persisted.
 	// They have the highest priority.
 	for {
@@ -839,6 +840,15 @@ func (db *DB) Compact() (returnErr error) {
 		return errors.Wrap(err, "WAL truncation in Compact")
 	}
 
+	compactionDuration := time.Since(start)
+	// TODO: change to milliseconds once fuzzit tests are removed
+	if int64(compactionDuration.Seconds())*1000 > db.head.chunkRange.Load() {
+		level.Warn(db.logger).Log(
+			"msg", "Head compaction took longer than the block time range, compactions are falling behind and won't be able to catch up",
+			"duration", compactionDuration.String(),
+			"block_range", db.head.chunkRange.Load(),
+		)
+	}
 	return db.compactBlocks()
 }