diff --git a/install.php b/install.php
index 3b854ee..2929ae6 100644
--- a/install.php
+++ b/install.php
@@ -99,18 +99,26 @@ class Install extends Controller {
             Debug::error( 'install hash not found on file.' );
             return false;
         }
-        if ( ! Session::exists( 'installHash' ) && ! Cookie::exists( 'installHash' ) ) {
+        $session = Session::get( 'installHash' );
+        $cookie = Cookie::get( 'installHash' );
+        $file = $this->installer->getNode('installHash');
+
+        if ( ! $session && ! $cookie ) {
             Debug::error( 'install hash not found in session or cookie.' );
             return false;
         }
-        if ( Cookie::exists( 'installHash' ) && !Session::exists( 'installHash' ) ) {
-            if ( Cookie::get( 'installHash' ) !== $this->installer->getNode('installHash') ) {
+        if ( $cookie && ! $session ) {
+            if ( $cookie !== $file ) {
+                Debug::error( 'install cookie did not match install file.' );
                 Cookie::delete( 'installHash' );
                 return false;
             }
-            Session::put( 'installHash', Cookie::get( 'installHash' ) );
+            Debug::error( 'cookie matches file, using as session' );
+            Session::put( 'installHash', $cookie );
+            return true;
         }
-        if ( Session::get( 'installHash' ) !== $this->installer->getNode('installHash') ) {
+        if ( $session !== $file ) {
+            Debug::error( 'session did not match file, deleting session' );
             Session::delete( 'installHash' );
             return false;
         }