diff --git a/NOnion/Cells/CellAuthChallenge.fs b/NOnion/Cells/CellAuthChallenge.fs
index a3c54c36..24fc0659 100644
--- a/NOnion/Cells/CellAuthChallenge.fs
+++ b/NOnion/Cells/CellAuthChallenge.fs
@@ -20,7 +20,7 @@ type CellAuthChallenge =
                 methods
             else
                 readMethod
-                    (methods @ [ ReadBigEndianUInt16 reader ])
+                    (ReadBigEndianUInt16 reader :: methods)
                     (remainingCount - 1)
 
         let challenge = reader.ReadBytes Constants.ChallangeLength
diff --git a/NOnion/Cells/CellCerts.fs b/NOnion/Cells/CellCerts.fs
index ea2ba8ab..afd1f674 100644
--- a/NOnion/Cells/CellCerts.fs
+++ b/NOnion/Cells/CellCerts.fs
@@ -33,7 +33,7 @@ type CellCerts =
                     }
 
                 readCertificates
-                    (certificates @ [ certificate ])
+                    (certificate :: certificates)
                     (remainingCount - 1)
 
         let certificatesCount = reader.ReadByte() |> int
diff --git a/NOnion/Cells/CellVersions.fs b/NOnion/Cells/CellVersions.fs
index 99111348..1c32caa3 100644
--- a/NOnion/Cells/CellVersions.fs
+++ b/NOnion/Cells/CellVersions.fs
@@ -22,7 +22,7 @@ type CellVersions =
             if reader.BaseStream.Length = reader.BaseStream.Position then
                 versions
             else
-                readVersions(versions @ [ ReadBigEndianUInt16 reader ])
+                readVersions((ReadBigEndianUInt16 reader) :: versions)
 
         let versions = readVersions List.empty
 
diff --git a/NOnion/Cells/Relay/RelayIntroduce.fs b/NOnion/Cells/Relay/RelayIntroduce.fs
index d45f3ada..181b3ff1 100644
--- a/NOnion/Cells/Relay/RelayIntroduce.fs
+++ b/NOnion/Cells/Relay/RelayIntroduce.fs
@@ -25,8 +25,7 @@ type RelayIntroduceInnerData =
                     state
                 else
                     readExtensionsList
-                        (state
-                         @ List.singleton(RelayIntroExtension.FromBytes reader))
+                        ((RelayIntroExtension.FromBytes reader) :: state)
                         (remainingCount - 1uy)
 
             readExtensionsList List.empty extensionCount
@@ -105,8 +104,7 @@ type RelayIntroduce =
                     state
                 else
                     readExtensionsList
-                        (state
-                         @ List.singleton(RelayIntroExtension.FromBytes reader))
+                        ((RelayIntroExtension.FromBytes reader)::state)
                         (remainingCount - 1uy)
 
             readExtensionsList List.empty extensionCount
diff --git a/NOnion/Cells/Relay/RelayIntroduceAck.fs b/NOnion/Cells/Relay/RelayIntroduceAck.fs
index 41407d8c..2f4f6e7f 100644
--- a/NOnion/Cells/Relay/RelayIntroduceAck.fs
+++ b/NOnion/Cells/Relay/RelayIntroduceAck.fs
@@ -33,8 +33,7 @@ type RelayIntroduceAck =
                     state
                 else
                     readExtensionsList
-                        (state
-                         @ List.singleton(RelayIntroExtension.FromBytes reader))
+                        (((RelayIntroExtension.FromBytes reader)) :: state)
                         (remainingCount - 1uy)
 
             readExtensionsList List.empty extensionCount
diff --git a/NOnion/Network/TorCircuit.fs b/NOnion/Network/TorCircuit.fs
index 0b81f7e4..234db142 100644
--- a/NOnion/Network/TorCircuit.fs
+++ b/NOnion/Network/TorCircuit.fs
@@ -673,17 +673,15 @@ type TorCircuit
                     circuitState <-
                         Ready(
                             circuitId,
-                            nodes
-                            @ List.singleton
-                                {
-                                    TorCircuitNode.CryptoState =
-                                        TorCryptoState.FromKdfResult
-                                            (Kdf.ComputeHSKdf ntorKeySeed)
-                                            true
-                                    Window =
-                                        TorWindow
-                                            Constants.DefaultCircuitLevelWindowParams
-                                }
+                            {
+                                TorCircuitNode.CryptoState =
+                                    TorCryptoState.FromKdfResult
+                                        (Kdf.ComputeHSKdf ntorKeySeed)
+                                        true
+                                Window =
+                                    TorWindow
+                                        Constants.DefaultCircuitLevelWindowParams
+                            } :: nodes
                         )
 
                     do!
@@ -785,17 +783,15 @@ type TorCircuit
                                 circuitState <-
                                     Ready(
                                         circuitId,
-                                        nodes
-                                        @ List.singleton
-                                            {
-                                                TorCircuitNode.CryptoState =
-                                                    TorCryptoState.FromKdfResult
-                                                        kdfResult
-                                                        false
-                                                Window =
-                                                    TorWindow
-                                                        Constants.DefaultCircuitLevelWindowParams
-                                            }
+                                        {
+                                            TorCircuitNode.CryptoState =
+                                                TorCryptoState.FromKdfResult
+                                                    kdfResult
+                                                    false
+                                            Window =
+                                                TorWindow
+                                                    Constants.DefaultCircuitLevelWindowParams
+                                        } :: nodes
                                     )
 
                                 tcs.SetResult circuitId
diff --git a/NOnion/Utility/Base32Util.fs b/NOnion/Utility/Base32Util.fs
index 2cb496a7..c9422f89 100644
--- a/NOnion/Utility/Base32Util.fs
+++ b/NOnion/Utility/Base32Util.fs
@@ -163,4 +163,4 @@ module Base32Util =
                         tail
                 | _ -> result
 
-            [ for c in text -> c ] |> parse [] |> List.toArray
+            [ for c in text -> c ] |> parse List.Empty |> List.toArray