diff --git a/RELEASE_NOTES.md b/RELEASE_NOTES.md
index 85bc526498..366b2d8e2a 100644
--- a/RELEASE_NOTES.md
+++ b/RELEASE_NOTES.md
@@ -1,5 +1,8 @@
+#### 1.3.20 - 06.05.2015
+* BUGFIX: Paket pack had issues with \ in subfolders - https://github.com/fsprojects/Paket/issues/812
+
 #### 1.3.19 - 05.05.2015
-* Fix: Find-Package-Versions command
+* BUGFIX: Find-Package-Versions command
 
 #### 1.3.18 - 05.05.2015
 * Use https://api.nuget.org/v3/index.json for Autocomplete
diff --git a/src/Paket.Core/NupkgWriter.fs b/src/Paket.Core/NupkgWriter.fs
index bde7de6fd5..7d4393d876 100644
--- a/src/Paket.Core/NupkgWriter.fs
+++ b/src/Paket.Core/NupkgWriter.fs
@@ -205,7 +205,7 @@ let Write (core : CompleteCoreInfo) optional workingDir outputDir =
         stream.Close()
 
     let ensureValidTargetName (target:string) =
-        match target.Replace(" ", "%20") with
+        match target.Replace(" ", "%20").Replace("\\", "/") with
         | t when t.EndsWith("/")         -> t
         | t when String.IsNullOrEmpty(t) -> ""
         | "."                            -> ""