diff --git a/dataplane/forwarding/fwdtable/prefix/prefix.go b/dataplane/forwarding/fwdtable/prefix/prefix.go
index cabab8590..408df80bf 100644
--- a/dataplane/forwarding/fwdtable/prefix/prefix.go
+++ b/dataplane/forwarding/fwdtable/prefix/prefix.go
@@ -134,7 +134,7 @@ func (t *Table) match(in []byte) (*key, fwdaction.Actions) {
 
 		// Strip out the prefix and check if the 0 or 1 child is a prefix for
 		// the new key.
-		key.TrimPrefix(curr.prefix)
+		key = key.TrimPrefix(curr.prefix)
 		curr = curr.child[key.Bit(0)]
 		if curr == nil {
 			break
@@ -160,7 +160,7 @@ func (t *Table) add(pre *key, actions fwdaction.Actions) {
 		}
 
 		// Strip out the prefix and determine the next level based on the 0th bit.
-		key.TrimPrefix(curr.prefix)
+		key = key.TrimPrefix(curr.prefix)
 		child := curr.child[key.Bit(0)]
 
 		// If the child does not exist, add the new level for the result.
@@ -183,7 +183,7 @@ func (t *Table) add(pre *key, actions fwdaction.Actions) {
 		// common prefix.
 		p := prefixKey(child.prefix, key)
 		curr = newLevel(p, curr)
-		child.prefix.TrimPrefix(p)
+		child.prefix = child.prefix.TrimPrefix(p)
 		curr.child[child.prefix.Bit(0)] = child
 		child.parent = curr
 	}
@@ -205,7 +205,7 @@ func (t *Table) remove(prefix *key) error {
 
 		// Strip out the prefix and check if the 0 or 1 child is a prefix for
 		// the new key.
-		key.TrimPrefix(curr.prefix)
+		key = key.TrimPrefix(curr.prefix)
 		if curr = curr.child[key.Bit(0)]; curr == nil {
 			return fmt.Errorf("prefix: Unable to find entry for prefix %v", key)
 		}
diff --git a/dataplane/forwarding/fwdtable/prefix/prefixkey.go b/dataplane/forwarding/fwdtable/prefix/prefixkey.go
index 2f51c0e98..20f5c93f8 100644
--- a/dataplane/forwarding/fwdtable/prefix/prefixkey.go
+++ b/dataplane/forwarding/fwdtable/prefix/prefixkey.go
@@ -159,10 +159,13 @@ func (s *key) Set(bitpos int, v byte) {
 	s.bytes.set(s.bitStart+bitpos, v)
 }
 
-// TrimPrefix removes a key which is known to be a prefix.
-func (s *key) TrimPrefix(q *key) {
-	s.bitCount -= q.bitCount
-	s.bitStart += q.bitCount
+// TrimPrefix removes a key which is known to be a prefix and returns a new key.
+func (s *key) TrimPrefix(q *key) *key {
+	return &key{
+		bytes:    s.bytes,
+		bitCount: s.bitCount - q.bitCount,
+		bitStart: s.bitStart + q.bitCount,
+	}
 }
 
 // BitCount returns the number of bits in the key.