diff --git a/RELEASE_NOTES.md b/RELEASE_NOTES.md
index d474c72044..2f3314ed15 100644
--- a/RELEASE_NOTES.md
+++ b/RELEASE_NOTES.md
@@ -1,4 +1,5 @@
-#### 3.2.0-alpha002 - 23.06.2016
+#### 3.2.0-alpha003 - 23.06.2016
+* Show out-of-sync error message if paket.lock is not matching paket.dependencies - https://github.com/fsprojects/Paket/issues/1750
 * BUGFIX: Don't report warnings for packages that are not installed for current target framework - https://github.com/fsprojects/Paket/issues/1693
 * BUGFIX: Runtime deps are copied based on TargetFramework - https://github.com/fsprojects/Paket/issues/1751
 * BUGFIX: Do not take over control over manual nodes - https://github.com/fsprojects/Paket/issues/1746
diff --git a/src/Paket.Core/DependencyChangeDetection.fs b/src/Paket.Core/DependencyChangeDetection.fs
index 0749a37b22..79ef99ff15 100644
--- a/src/Paket.Core/DependencyChangeDetection.fs
+++ b/src/Paket.Core/DependencyChangeDetection.fs
@@ -175,3 +175,44 @@ let GetPreferredNuGetVersions (dependenciesFile:DependenciesFile,lockFile:LockFi
             | Some s -> kv.Key, (kv.Value.Version, s)
             | None -> kv.Key, (kv.Value.Version, kv.Value.Source))
     |> Map.ofSeq
+
+let GetChanges(dependenciesFile,lockFile) =
+    let nuGetChanges = findNuGetChangesInDependenciesFile(dependenciesFile,lockFile)
+    let nuGetChangesPerGroup =
+        nuGetChanges
+        |> Seq.groupBy fst
+        |> Map.ofSeq
+
+    let remoteFileChanges = findRemoteFileChangesInDependenciesFile(dependenciesFile,lockFile)
+    let remoteFileChangesPerGroup =
+        remoteFileChanges
+        |> Seq.groupBy fst
+        |> Map.ofSeq
+
+    let hasNuGetChanges groupName =
+        match nuGetChangesPerGroup |> Map.tryFind groupName with
+        | None -> false
+        | Some x -> Seq.isEmpty x |> not
+
+    let hasRemoteFileChanges groupName =
+        match remoteFileChangesPerGroup |> Map.tryFind groupName with
+        | None -> false
+        | Some x -> Seq.isEmpty x |> not
+
+    let hasChangedSettings groupName =
+        match dependenciesFile.Groups |> Map.tryFind groupName with
+        | None -> true
+        | Some dependenciesFileGroup -> 
+            match lockFile.Groups |> Map.tryFind groupName with
+            | None -> true
+            | Some lockFileGroup -> dependenciesFileGroup.Options <> lockFileGroup.Options
+
+    let hasChanges groupName _ = hasChangedSettings groupName || hasNuGetChanges groupName || hasRemoteFileChanges groupName
+
+    let hasAnyChanges =
+        dependenciesFile.Groups
+        |> Map.filter hasChanges
+        |> Map.isEmpty
+        |> not
+
+    hasAnyChanges,nuGetChanges,remoteFileChanges,hasChanges
\ No newline at end of file
diff --git a/src/Paket.Core/RestoreProcess.fs b/src/Paket.Core/RestoreProcess.fs
index 50681dcdd2..e462a27ebf 100644
--- a/src/Paket.Core/RestoreProcess.fs
+++ b/src/Paket.Core/RestoreProcess.fs
@@ -128,7 +128,12 @@ let Restore(dependenciesFileName,force,group,referencesFileNames) =
     let lockFile = 
         LockFile.LoadFrom(lockFileName.FullName)
         |> LocalFile.overrideLockFile localFile
-   
+
+    let hasAnyChanges,_,_,_ = DependencyChangeDetection.GetChanges(dependenciesFile,lockFile)
+
+    if hasAnyChanges then 
+        failwithf "paket.dependencies and paket.lock are out of sync in %s.%sPlease run 'paket install' or 'paket update' to recompute the paket.lock file." lockFileName.Directory.FullName Environment.NewLine
+
     let groups =
         match group with
         | None -> lockFile.Groups 
diff --git a/src/Paket.Core/UpdateProcess.fs b/src/Paket.Core/UpdateProcess.fs
index 9e0edbfca8..e102231a3d 100644
--- a/src/Paket.Core/UpdateProcess.fs
+++ b/src/Paket.Core/UpdateProcess.fs
@@ -85,38 +85,10 @@ let selectiveUpdate force getSha1 getSortedVersionsF getPackageDetailsF (lockFil
 
                 changes,groups
             | Install ->
-                let nuGetChanges = DependencyChangeDetection.findNuGetChangesInDependenciesFile(dependenciesFile,lockFile)
-                let nuGetChangesPerGroup =
-                    nuGetChanges
-                    |> Seq.groupBy fst
-                    |> Map.ofSeq
-
-                let remoteFileChanges = DependencyChangeDetection.findRemoteFileChangesInDependenciesFile(dependenciesFile,lockFile)
-                let remoteFileChangesPerGroup =
-                    remoteFileChanges
-                    |> Seq.groupBy fst
-                    |> Map.ofSeq
-
-                let hasNuGetChanges groupName =
-                    match nuGetChangesPerGroup |> Map.tryFind groupName with
-                    | None -> false
-                    | Some x -> Seq.isEmpty x |> not
-
-                let hasRemoteFileChanges groupName =
-                    match remoteFileChangesPerGroup |> Map.tryFind groupName with
-                    | None -> false
-                    | Some x -> Seq.isEmpty x |> not
-
-                let hasChangedSettings groupName =
-                    match dependenciesFile.Groups |> Map.tryFind groupName with
-                    | None -> true
-                    | Some dependenciesFileGroup -> 
-                        match lockFile.Groups |> Map.tryFind groupName with
-                        | None -> true
-                        | Some lockFileGroup -> dependenciesFileGroup.Options <> lockFileGroup.Options
-
-                let hasChanges groupName _ = 
-                    let hasChanges = hasChangedSettings groupName || hasNuGetChanges groupName || hasRemoteFileChanges groupName
+                let hasAnyChanges,nuGetChanges,remoteFileChanges,hasChanges = DependencyChangeDetection.GetChanges(dependenciesFile,lockFile)
+
+                let hasChanges groupName x = 
+                    let hasChanges = hasChanges groupName x
                     if not hasChanges then
                         tracefn "Skipping resolver for group %O since it is already up-to-date" groupName
                     hasChanges
diff --git a/src/Paket/Paket.fsproj b/src/Paket/Paket.fsproj
index f24bc36b97..c30797909d 100644
--- a/src/Paket/Paket.fsproj
+++ b/src/Paket/Paket.fsproj
@@ -51,8 +51,8 @@
     <StartWorkingDirectory>D:\code\PaketKopie</StartWorkingDirectory>
     <StartArguments>update -f</StartArguments>
     <StartWorkingDirectory>D:\code\Paket\integrationtests\scenarios\i001117-aws\temp</StartWorkingDirectory>
-    <StartArguments>update</StartArguments>
-    <StartWorkingDirectory>D:\code\Paket\integrationtests\scenarios\i001442-warn-Rx\temp</StartWorkingDirectory>
+    <StartArguments>restore</StartArguments>
+    <StartWorkingDirectory>D:\code\paket3dotnetcoreissue</StartWorkingDirectory>
   </PropertyGroup>
   <PropertyGroup>
     <MinimumVisualStudioVersion Condition="'$(MinimumVisualStudioVersion)' == ''">11</MinimumVisualStudioVersion>