diff --git a/src/CosmoStore.CosmosDb/Conversion.fs b/src/CosmoStore.CosmosDb/Conversion.fs
index c6b0ed0..c76f752 100644
--- a/src/CosmoStore.CosmosDb/Conversion.fs
+++ b/src/CosmoStore.CosmosDb/Conversion.fs
@@ -5,18 +5,6 @@ open CosmoStore
 open Microsoft.Azure.Documents
 open Newtonsoft.Json.Linq
 
-let eventWriteToEventRead streamId position createdUtc (x:EventWrite) = {
-    Id = x.Id
-    CorrelationId = x.CorrelationId
-    CausationId = x.CausationId
-    StreamId = streamId
-    Position = position
-    Name = x.Name
-    Data = x.Data
-    Metadata = x.Metadata
-    CreatedUtc = createdUtc
-}
-
 let documentToStream (x:Document) = {
     Id = x.GetPropertyValue<string>("streamId")
     LastUpdatedUtc = x.GetPropertyValue<DateTime>("lastUpdatedUtc")
diff --git a/src/CosmoStore.CosmosDb/EventStore.fs b/src/CosmoStore.CosmosDb/EventStore.fs
index 7ea5e0a..698bf09 100644
--- a/src/CosmoStore.CosmosDb/EventStore.fs
+++ b/src/CosmoStore.CosmosDb/EventStore.fs
@@ -5,6 +5,7 @@ open Microsoft.Azure.Documents
 open Microsoft.Azure.Documents.Client
 open FSharp.Control.Tasks.V2
 open CosmoStore
+open CosmoStore.Helper
 open System.Reflection
 open System.IO
 open CosmoStore.CosmosDb
@@ -76,7 +77,7 @@ let private appendEvents getOpts (client:DocumentClient) (storedProcUri:Uri) (st
         return resp.Response 
         |> List.map toPositionAndDate 
         |> List.zip events
-        |> List.map (fun (evn,(pos,created)) -> Conversion.eventWriteToEventRead streamId pos created evn)
+        |> List.map (fun (evn,(pos,created)) -> eventWriteToEventRead streamId pos created evn)
     }
 
 let private streamsReadToQuery = function
diff --git a/src/CosmoStore.InMemory/EventStore.fs b/src/CosmoStore.InMemory/EventStore.fs
index dc63268..f232177 100644
--- a/src/CosmoStore.InMemory/EventStore.fs
+++ b/src/CosmoStore.InMemory/EventStore.fs
@@ -1,35 +1,13 @@
 namespace CosmoStore.InMemory
 open System
 open CosmoStore
+open CosmoStore.Helper
 open FSharp.Control.Tasks.V2
 open System.Reactive.Linq
 open System.Reactive.Concurrency
 
 
 module EventStore =
-    let private validatePosition streamId (nextPos: int64) = function
-        | ExpectedPosition.Any -> ()
-        | ExpectedPosition.NoStream ->
-            if nextPos > 1L then
-                failwithf "ESERROR_POSITION_STREAMEXISTS: Stream '%s' was expected to be empty, but contains %i events" streamId (nextPos - 1L)
-        | ExpectedPosition.Exact expectedPos ->
-            if nextPos <> expectedPos then
-                failwithf "ESERROR_POSITION_POSITIONNOTMATCH: Stream '%s' was expected to have next position %i, but has %i" streamId expectedPos nextPos
-
-
-    let checkNull a = obj.ReferenceEquals(a, null)
-
-    let eventWriteToEventRead streamId position createdUtc (x: EventWrite) = {
-        Id = x.Id
-        CorrelationId = x.CorrelationId
-        CausationId = x.CausationId
-        StreamId = streamId
-        Position = position
-        Name = x.Name
-        Data = x.Data
-        Metadata = x.Metadata
-        CreatedUtc = createdUtc
-    }
 
     type StreamData = {
         StreamStore: StreamStoreType
diff --git a/src/CosmoStore.Marten/EventStore.fs b/src/CosmoStore.Marten/EventStore.fs
index 9700e97..60baa68 100644
--- a/src/CosmoStore.Marten/EventStore.fs
+++ b/src/CosmoStore.Marten/EventStore.fs
@@ -8,35 +8,11 @@ module EventStore =
     open Marten
     open System.Linq
     open CosmoStore
+    open CosmoStore.Helper
     open FSharp.Control.Tasks.V2.ContextInsensitive
     open System.Reactive.Linq
     open System.Reactive.Concurrency
 
-
-    let private validatePosition streamId (nextPos: int64) = function
-        | ExpectedPosition.Any -> ()
-        | ExpectedPosition.NoStream ->
-            if nextPos > 1L then
-                failwithf "ESERROR_POSITION_STREAMEXISTS: Stream '%s' was expected to be empty, but contains %i events" streamId (nextPos - 1L)
-        | ExpectedPosition.Exact expectedPos ->
-            if nextPos <> expectedPos then
-                failwithf "ESERROR_POSITION_POSITIONNOTMATCH: Stream '%s' was expected to have next position %i, but has %i" streamId expectedPos nextPos
-
-
-    let checkNull a = obj.ReferenceEquals(a, null)
-
-    let eventWriteToEventRead streamId position createdUtc (x: EventWrite) = {
-        Id = x.Id
-        CorrelationId = x.CorrelationId
-        CausationId = x.CausationId
-        StreamId = streamId
-        Position = position
-        Name = x.Name
-        Data = x.Data
-        Metadata = x.Metadata
-        CreatedUtc = createdUtc
-    }
-
     type StreamData = {
         Store: IDocumentStore
         StreamId: string
diff --git a/src/CosmoStore.TableStorage/EventStore.fs b/src/CosmoStore.TableStorage/EventStore.fs
index 40a137c..d9c1996 100644
--- a/src/CosmoStore.TableStorage/EventStore.fs
+++ b/src/CosmoStore.TableStorage/EventStore.fs
@@ -4,6 +4,7 @@ open System
 open Microsoft.WindowsAzure.Storage
 open Microsoft.WindowsAzure.Storage.Table
 open CosmoStore
+open CosmoStore.Helper
 open FSharp.Control.Tasks.V2
 open CosmoStore.TableStorage
 open System.Reactive.Linq
@@ -20,14 +21,6 @@ let private tryGetStreamMetadata (table:CloudTable) (streamId:string) =
             return (entity, entity |> Conversion.entityToStream) |> Some
     }
 
-let private validatePosition streamId (nextPos:int64) = function
-    | ExpectedPosition.Any -> ()
-    | ExpectedPosition.NoStream -> 
-        if nextPos > 1L then 
-            failwithf "ESERROR_POSITION_STREAMEXISTS: Stream '%s' was expected to be empty, but contains %i events" streamId (nextPos - 1L)
-    | ExpectedPosition.Exact expectedPos ->
-        if nextPos <> expectedPos then
-            failwithf "ESERROR_POSITION_POSITIONNOTMATCH: Stream '%s' was expected to have next position %i, but has %i" streamId expectedPos nextPos
 
 let private appendEvents (table:CloudTable) (streamId:string) (expectedPosition:ExpectedPosition) (events:EventWrite list) =
     
diff --git a/src/CosmoStore/CosmoStore.fs b/src/CosmoStore/CosmoStore.fs
index bca3bba..82819f0 100644
--- a/src/CosmoStore/CosmoStore.fs
+++ b/src/CosmoStore/CosmoStore.fs
@@ -57,4 +57,29 @@ type EventStore = {
     GetStreams : StreamsReadFilter -> Task<Stream list>
     GetStream : string -> Task<Stream>
     EventAppended : IObservable<EventRead>
-}
\ No newline at end of file
+}
+
+module Helper =
+    let validatePosition streamId (nextPos: int64) = function
+        | ExpectedPosition.Any -> ()
+        | ExpectedPosition.NoStream ->
+            if nextPos > 1L then
+                failwithf "ESERROR_POSITION_STREAMEXISTS: Stream '%s' was expected to be empty, but contains %i events" streamId (nextPos - 1L)
+        | ExpectedPosition.Exact expectedPos ->
+            if nextPos <> expectedPos then
+                failwithf "ESERROR_POSITION_POSITIONNOTMATCH: Stream '%s' was expected to have next position %i, but has %i" streamId expectedPos nextPos
+
+
+    let checkNull a = obj.ReferenceEquals(a, null)
+
+    let eventWriteToEventRead streamId position createdUtc (x: EventWrite) = {
+        Id = x.Id
+        CorrelationId = x.CorrelationId
+        CausationId = x.CausationId
+        StreamId = streamId
+        Position = position
+        Name = x.Name
+        Data = x.Data
+        Metadata = x.Metadata
+        CreatedUtc = createdUtc
+    }
\ No newline at end of file