diff --git a/internal/mempool/mempool.go b/internal/mempool/mempool.go
index 19300d911..b47f69d29 100644
--- a/internal/mempool/mempool.go
+++ b/internal/mempool/mempool.go
@@ -362,8 +362,8 @@ func (txmp *TxMempool) Flush() {
 //   - Transactions returned are not removed from the mempool transaction
 //     store or indexes.
 func (txmp *TxMempool) ReapMaxBytesMaxGas(maxBytes, maxGas int64) types.Txs {
-	txmp.mtx.RLock()
-	defer txmp.mtx.RUnlock()
+	txmp.mtx.Lock()
+	defer txmp.mtx.Unlock()
 
 	var (
 		totalGas  int64
@@ -417,8 +417,8 @@ func (txmp *TxMempool) ReapMaxBytesMaxGas(maxBytes, maxGas int64) types.Txs {
 //   - Transactions returned are not removed from the mempool transaction
 //     store or indexes.
 func (txmp *TxMempool) ReapMaxTxs(max int) types.Txs {
-	txmp.mtx.RLock()
-	defer txmp.mtx.RUnlock()
+	txmp.mtx.Lock()
+	defer txmp.mtx.Unlock()
 
 	numTxs := txmp.priorityIndex.NumTxs()
 	if max < 0 {
diff --git a/internal/mempool/mempool_test.go b/internal/mempool/mempool_test.go
index 487f00654..76e89c056 100644
--- a/internal/mempool/mempool_test.go
+++ b/internal/mempool/mempool_test.go
@@ -304,27 +304,43 @@ func TestTxMempool_ReapMaxBytesMaxGas(t *testing.T) {
 		require.Equal(t, priorities[:len(reapedPriorities)], reapedPriorities)
 	}
 
+	var wg sync.WaitGroup
+
 	// reap by gas capacity only
-	reapedTxs := txmp.ReapMaxBytesMaxGas(-1, 50)
-	ensurePrioritized(reapedTxs)
-	require.Equal(t, len(tTxs), txmp.Size())
-	require.Equal(t, int64(5690), txmp.SizeBytes())
-	require.Len(t, reapedTxs, 50)
+	wg.Add(1)
+	go func() {
+		defer wg.Done()
+		reapedTxs := txmp.ReapMaxBytesMaxGas(-1, 50)
+		ensurePrioritized(reapedTxs)
+		require.Equal(t, len(tTxs), txmp.Size())
+		require.Equal(t, int64(5690), txmp.SizeBytes())
+		require.Len(t, reapedTxs, 50)
+	}()
 
 	// reap by transaction bytes only
-	reapedTxs = txmp.ReapMaxBytesMaxGas(1000, -1)
-	ensurePrioritized(reapedTxs)
-	require.Equal(t, len(tTxs), txmp.Size())
-	require.Equal(t, int64(5690), txmp.SizeBytes())
-	require.GreaterOrEqual(t, len(reapedTxs), 16)
+	wg.Add(1)
+	go func() {
+		defer wg.Done()
+		reapedTxs := txmp.ReapMaxBytesMaxGas(1000, -1)
+		ensurePrioritized(reapedTxs)
+		require.Equal(t, len(tTxs), txmp.Size())
+		require.Equal(t, int64(5690), txmp.SizeBytes())
+		require.GreaterOrEqual(t, len(reapedTxs), 16)
+	}()
 
 	// Reap by both transaction bytes and gas, where the size yields 31 reaped
 	// transactions and the gas limit reaps 25 transactions.
-	reapedTxs = txmp.ReapMaxBytesMaxGas(1500, 30)
-	ensurePrioritized(reapedTxs)
-	require.Equal(t, len(tTxs), txmp.Size())
-	require.Equal(t, int64(5690), txmp.SizeBytes())
-	require.Len(t, reapedTxs, 25)
+	wg.Add(1)
+	go func() {
+		defer wg.Done()
+		reapedTxs := txmp.ReapMaxBytesMaxGas(1500, 30)
+		ensurePrioritized(reapedTxs)
+		require.Equal(t, len(tTxs), txmp.Size())
+		require.Equal(t, int64(5690), txmp.SizeBytes())
+		require.Len(t, reapedTxs, 25)
+	}()
+
+	wg.Wait()
 }
 
 func TestTxMempool_ReapMaxTxs(t *testing.T) {
@@ -363,26 +379,42 @@ func TestTxMempool_ReapMaxTxs(t *testing.T) {
 		require.Equal(t, priorities[:len(reapedPriorities)], reapedPriorities)
 	}
 
+	var wg sync.WaitGroup
+
 	// reap all transactions
-	reapedTxs := txmp.ReapMaxTxs(-1)
-	ensurePrioritized(reapedTxs)
-	require.Equal(t, len(tTxs), txmp.Size())
-	require.Equal(t, int64(5690), txmp.SizeBytes())
-	require.Len(t, reapedTxs, len(tTxs))
+	wg.Add(1)
+	go func() {
+		defer wg.Done()
+		reapedTxs := txmp.ReapMaxTxs(-1)
+		ensurePrioritized(reapedTxs)
+		require.Equal(t, len(tTxs), txmp.Size())
+		require.Equal(t, int64(5690), txmp.SizeBytes())
+		require.Len(t, reapedTxs, len(tTxs))
+	}()
 
 	// reap a single transaction
-	reapedTxs = txmp.ReapMaxTxs(1)
-	ensurePrioritized(reapedTxs)
-	require.Equal(t, len(tTxs), txmp.Size())
-	require.Equal(t, int64(5690), txmp.SizeBytes())
-	require.Len(t, reapedTxs, 1)
+	wg.Add(1)
+	go func() {
+		defer wg.Done()
+		reapedTxs := txmp.ReapMaxTxs(1)
+		ensurePrioritized(reapedTxs)
+		require.Equal(t, len(tTxs), txmp.Size())
+		require.Equal(t, int64(5690), txmp.SizeBytes())
+		require.Len(t, reapedTxs, 1)
+	}()
 
 	// reap half of the transactions
-	reapedTxs = txmp.ReapMaxTxs(len(tTxs) / 2)
-	ensurePrioritized(reapedTxs)
-	require.Equal(t, len(tTxs), txmp.Size())
-	require.Equal(t, int64(5690), txmp.SizeBytes())
-	require.Len(t, reapedTxs, len(tTxs)/2)
+	wg.Add(1)
+	go func() {
+		defer wg.Done()
+		reapedTxs := txmp.ReapMaxTxs(len(tTxs) / 2)
+		ensurePrioritized(reapedTxs)
+		require.Equal(t, len(tTxs), txmp.Size())
+		require.Equal(t, int64(5690), txmp.SizeBytes())
+		require.Len(t, reapedTxs, len(tTxs)/2)
+	}()
+
+	wg.Wait()
 }
 
 func TestTxMempool_CheckTxExceedsMaxSize(t *testing.T) {