diff --git a/src/Composer/DependencyResolver/LockTransaction.php b/src/Composer/DependencyResolver/LockTransaction.php
index 3d5204067..a0aa4cd7e 100644
--- a/src/Composer/DependencyResolver/LockTransaction.php
+++ b/src/Composer/DependencyResolver/LockTransaction.php
@@ -137,6 +137,7 @@ class LockTransaction
 
         foreach ($packages as $package) {
             foreach ($this->resultPackages['dev'] as $i => $resultPackage) {
+                // TODO this comparison is probably insufficient, aliases, what about modified versions? I guess they aren't possible?
                 if ($package->getName() == $resultPackage->getName()) {
                     $this->resultPackages['non-dev'][] = $resultPackage;
                     unset($this->resultPackages['dev'][$i]);
diff --git a/src/Composer/DependencyResolver/Problem.php b/src/Composer/DependencyResolver/Problem.php
index e07d4d0c1..2c1c7236a 100644
--- a/src/Composer/DependencyResolver/Problem.php
+++ b/src/Composer/DependencyResolver/Problem.php
@@ -90,7 +90,7 @@ class Problem
                 $packages = array();
             }
 
-            if ($job && $job['cmd'] === 'install' && empty($packages)) {
+            if ($job && ($job['cmd'] === 'install' || $job['cmd'] === 'fix') && empty($packages)) {
 
                 // handle php/hhvm
                 if ($packageName === 'php' || $packageName === 'php-64bit' || $packageName === 'hhvm') {
@@ -208,6 +208,13 @@ class Problem
         $packageName = $job['packageName'];
         $constraint = $job['constraint'];
         switch ($job['cmd']) {
+            case 'fix':
+                $package = $job['package'];
+                if ($job['lockable']) {
+                    return 'Package '.$package->getPrettyName().' is locked to version '.$package->getPrettyVersion();
+                } else {
+                    return 'Package '.$package->getPrettyName().' is present at version '.$package->getPrettyVersion() . ' and cannot be modified by Composer';
+                }
             case 'install':
                 $packages = $this->pool->whatProvides($packageName, $constraint);
                 if (!$packages) {
diff --git a/src/Composer/DependencyResolver/RuleSetGenerator.php b/src/Composer/DependencyResolver/RuleSetGenerator.php
index 64cb27b11..0c7350cdd 100644
--- a/src/Composer/DependencyResolver/RuleSetGenerator.php
+++ b/src/Composer/DependencyResolver/RuleSetGenerator.php
@@ -12,9 +12,11 @@
 
 namespace Composer\DependencyResolver;
 
+use Composer\Package\LinkConstraint\VersionConstraint;
 use Composer\Package\PackageInterface;
 use Composer\Package\AliasPackage;
 use Composer\Repository\PlatformRepository;
+use Composer\Semver\Constraint\Constraint;
 
 /**
  * @author Nils Adermann <naderman@naderman.de>
@@ -254,8 +256,10 @@ class RuleSetGenerator
         return $impossible;
     }
 
-    protected function addRulesForRequest($request, $ignorePlatformReqs)
+    protected function addRulesForRequest(Request $request, $ignorePlatformReqs)
     {
+        $unlockableMap = $request->getUnlockableMap();
+
         foreach ($request->getFixedPackages() as $package) {
             $this->addRulesForPackage($package, $ignorePlatformReqs);
 
@@ -263,6 +267,8 @@ class RuleSetGenerator
                 'cmd' => 'fix',
                 'packageName' => $package->getName(),
                 'constraint' => null,
+                'package' => $package,
+                'lockable' => !isset($unlockableMap[$package->id]),
                 'fixed' => true
             ));
             $this->addRule(RuleSet::TYPE_JOB, $rule);
diff --git a/tests/Composer/Test/Fixtures/installer/install-from-lock-removes-package.test b/tests/Composer/Test/Fixtures/installer/install-from-lock-removes-package.test
index 6063abfee..83569bfe7 100644
--- a/tests/Composer/Test/Fixtures/installer/install-from-lock-removes-package.test
+++ b/tests/Composer/Test/Fixtures/installer/install-from-lock-removes-package.test
@@ -25,7 +25,7 @@ Install from a lock file that deleted a package
         { "name": "whitelisted", "version": "1.1.0" },
         { "name": "fixed-dependency", "version": "1.0.0" }
     ],
-    "packages-dev": null,
+    "packages-dev": [],
     "aliases": [],
     "minimum-stability": "dev",
     "stability-flags": [],
diff --git a/tests/Composer/Test/Fixtures/installer/partial-update-without-lock.test b/tests/Composer/Test/Fixtures/installer/partial-update-without-lock.test
index e931a1f7d..845005649 100644
--- a/tests/Composer/Test/Fixtures/installer/partial-update-without-lock.test
+++ b/tests/Composer/Test/Fixtures/installer/partial-update-without-lock.test
@@ -28,6 +28,23 @@ Partial update without lock file should update everything whitelisted, remove ov
     { "name": "c/uptodate", "version": "1.0.0" },
     { "name": "d/removed", "version": "1.0.0" }
 ]
+--LOCK--
+{
+    "packages": [
+        { "name": "a/old", "version": "1.0.0" },
+        { "name": "b/unstable", "version": "1.1.0-alpha" },
+        { "name": "c/uptodate", "version": "1.0.0" },
+        { "name": "d/removed", "version": "1.0.0" }
+    ],
+    "packages-dev": [],
+    "aliases": [],
+    "minimum-stability": "dev",
+    "stability-flags": [],
+    "prefer-stable": false,
+    "prefer-lowest": false,
+    "platform": [],
+    "platform-dev": []
+}
 --RUN--
 update b/unstable
 --EXPECT-LOCK--
diff --git a/tests/Composer/Test/Fixtures/installer/solver-problems.test b/tests/Composer/Test/Fixtures/installer/solver-problems.test
index 8b1336db2..b6d2180db 100644
--- a/tests/Composer/Test/Fixtures/installer/solver-problems.test
+++ b/tests/Composer/Test/Fixtures/installer/solver-problems.test
@@ -30,6 +30,21 @@ Test the error output of solver problems.
     { "name": "stable-requiree-excluded/pkg", "version": "1.0.0" }
 ]
 
+--LOCK--
+{
+    "packages": [
+        { "name": "stable-requiree-excluded/pkg", "version": "1.0.0" }
+    ],
+    "packages-dev": [],
+    "aliases": [],
+    "minimum-stability": "dev",
+    "stability-flags": [],
+    "prefer-stable": false,
+    "prefer-lowest": false,
+    "platform": [],
+    "platform-dev": []
+}
+
 --RUN--
 update unstable/package requirer/pkg dependency/pkg
 
@@ -38,7 +53,7 @@ update unstable/package requirer/pkg dependency/pkg
 
 --EXPECT-OUTPUT--
 Loading composer repositories with package information
-Updating dependencies (including require-dev)
+Updating dependencies
 Your requirements could not be resolved to an installable set of packages.
 
   Problem 1
diff --git a/tests/Composer/Test/Fixtures/installer/update-with-all-dependencies.test b/tests/Composer/Test/Fixtures/installer/update-with-all-dependencies.test
index c0019e6ca..14d8e13d8 100644
--- a/tests/Composer/Test/Fixtures/installer/update-with-all-dependencies.test
+++ b/tests/Composer/Test/Fixtures/installer/update-with-all-dependencies.test
@@ -28,15 +28,33 @@ When `--with-all-dependencies` is used, Composer\Installer::whitelistUpdateDepen
     { "name": "a/a", "version": "1.0.0" },
     { "name": "b/b", "version": "1.0.0", "require": { "a/a": "~1.0" } }
 ]
-
+--LOCK--
+{
+    "packages": [
+        { "name": "a/a", "version": "1.0.0" },
+        { "name": "b/b", "version": "1.0.0", "require": { "a/a": "~1.0" } }
+    ],
+    "packages-dev": [],
+    "aliases": [],
+    "minimum-stability": "dev",
+    "stability-flags": [],
+    "prefer-stable": false,
+    "prefer-lowest": false,
+    "platform": [],
+    "platform-dev": []
+}
 --RUN--
 update b/b --with-all-dependencies
 
 --EXPECT-OUTPUT--
 Loading composer repositories with package information
-Updating dependencies (including require-dev)
-Package operations: 0 installs, 2 updates, 0 removals
+Updating dependencies
+Lock file operations: 0 installs, 2 updates, 0 removals
+  - Updating b/b (1.0.0) to b/b (1.1.0)
+  - Updating a/a (1.0.0) to a/a (1.1.0)
 Writing lock file
+Installing dependencies from lock file (including require-dev)
+Package operations: 0 installs, 2 updates, 0 removals
 Generating autoload files
 
 --EXPECT--