diff --git a/core/src/core/transaction.rs b/core/src/core/transaction.rs
index 0ff9779bf9..cd5070a6b4 100644
--- a/core/src/core/transaction.rs
+++ b/core/src/core/transaction.rs
@@ -964,6 +964,12 @@ impl Transaction {
 		Ok(())
 	}
 
+	/// Can be used to compare txs by their fee/weight ratio.
+	/// Don't use these values for anything else though due to precision multiplier.
+	pub fn fee_to_weight(&self) -> u64 {
+		self.fee() * 1_000 / self.tx_weight() as u64
+	}
+
 	/// Calculate transaction weight
 	pub fn tx_weight(&self) -> usize {
 		self.body.body_weight()
diff --git a/pool/src/pool.rs b/pool/src/pool.rs
index a7d355f928..757bfd0792 100644
--- a/pool/src/pool.rs
+++ b/pool/src/pool.rs
@@ -132,7 +132,7 @@ impl Pool {
 		// Sort them by fees over weight, multiplying by 1000 to keep some precision
 		// don't think we'll ever see a >max_u64/1000 fee transaction.
 		// We want to select the txs with highest fee per unit of weight first.
-		tx_buckets.sort_unstable_by_key(|tx| tx.fee() * 1000 / tx.tx_weight() as u64);
+		tx_buckets.sort_unstable_by_key(|tx| tx.fee_to_weight());
 
 		// Iteratively apply the txs to the current chain state,
 		// rejecting any that do not result in a valid state.
@@ -364,8 +364,11 @@ impl Pool {
 					// We found a single parent tx, so aggregate in the bucket
 					// if the aggregate tx is a valid tx.
 					// Otherwise discard and let the next block pick this tx up.
-					let current = tx_buckets[pos].clone();
-					if let Ok(agg_tx) = transaction::aggregate(vec![current, entry.tx.clone()]) {
+					let ref current = tx_buckets[pos];
+
+					if let Ok(agg_tx) =
+						transaction::aggregate(vec![current.clone(), entry.tx.clone()])
+					{
 						if agg_tx
 							.validate(
 								Weighting::AsLimitedTransaction { max_weight },
@@ -373,7 +376,12 @@ impl Pool {
 							)
 							.is_ok()
 						{
-							tx_buckets[pos] = agg_tx;
+							// Only aggregate if it does not reduce the fee_to_weight ratio.
+							if agg_tx.fee_to_weight() >= current.fee_to_weight() {
+								tx_buckets[pos] = agg_tx;
+							} else {
+								tx_buckets.push(entry.tx.clone());
+							}
 						} else {
 							// Aggregated tx is not valid so discard this new tx.
 							is_rejected = true;