diff --git a/src/Psalm/Codebase/Populator.php b/src/Psalm/Codebase/Populator.php
index 49f3cfde9..df739804f 100644
--- a/src/Psalm/Codebase/Populator.php
+++ b/src/Psalm/Codebase/Populator.php
@@ -77,7 +77,7 @@ class Populator
             echo 'ClassLikeStorage is populating' . "\n";
         }
 
-        foreach ($this->classlike_storage_provider->getAll() as $class_storage) {
+        foreach ($this->classlike_storage_provider->getNew() as $class_storage) {
             if (!$class_storage->user_defined && !$class_storage->stubbed) {
                 continue;
             }
@@ -93,14 +93,13 @@ class Populator
             echo 'FileStorage is populating' . "\n";
         }
 
-        $all_file_storage = $this->file_storage_provider->getAll();
+        $all_file_storage = $this->file_storage_provider->getNew();
 
         foreach ($all_file_storage as $file_storage) {
             $this->populateFileStorage($file_storage);
         }
 
-
-        foreach ($this->classlike_storage_provider->getAll() as $class_storage) {
+        foreach ($this->classlike_storage_provider->getNew() as $class_storage) {
             if ($this->config->allow_phpstorm_generics) {
                 foreach ($class_storage->properties as $property_storage) {
                     if ($property_storage->type) {
@@ -182,6 +181,9 @@ class Populator
         if ($this->debug_output) {
             echo 'FileStorage is populated' . "\n";
         }
+
+        $this->classlike_storage_provider->populated();
+        $this->file_storage_provider->populated();
     }
 
     /**
diff --git a/src/Psalm/Provider/ClassLikeStorageProvider.php b/src/Psalm/Provider/ClassLikeStorageProvider.php
index 3dd1561b8..4e2c88912 100644
--- a/src/Psalm/Provider/ClassLikeStorageProvider.php
+++ b/src/Psalm/Provider/ClassLikeStorageProvider.php
@@ -12,6 +12,11 @@ class ClassLikeStorageProvider
      */
     private static $storage = [];
 
+    /**
+     * @var array<string, ClassLikeStorage>
+     */
+    private static $new_storage = [];
+
     /**
      * @var ?ClassLikeStorageCacheProvider
      */
@@ -69,9 +74,10 @@ class ClassLikeStorageProvider
             throw new \LogicException('Cannot exhume when there’s no cache');
         }
 
-        self::$storage[$fq_classlike_name_lc]
-            = $cached_value
-            = $this->cache->getLatestFromCache($fq_classlike_name_lc, $file_path, $file_contents);
+        $cached_value = $this->cache->getLatestFromCache($fq_classlike_name_lc, $file_path, $file_contents);
+
+        self::$storage[$fq_classlike_name_lc] =  $cached_value;
+        self::$new_storage[$fq_classlike_name_lc] =  $cached_value;
 
         return $cached_value;
     }
@@ -84,12 +90,21 @@ class ClassLikeStorageProvider
         return self::$storage;
     }
 
+    /**
+     * @return array<string, ClassLikeStorage>
+     */
+    public function getNew()
+    {
+        return self::$new_storage;
+    }
+
     /**
      * @param array<string, ClassLikeStorage> $more
      * @return void
      */
     public function addMore(array $more)
     {
+        self::$new_storage = array_merge($more, self::$new_storage);
         self::$storage = array_merge($more, self::$storage);
     }
 
@@ -102,7 +117,9 @@ class ClassLikeStorageProvider
     {
         $fq_classlike_name_lc = strtolower($fq_classlike_name);
 
-        self::$storage[$fq_classlike_name_lc] = $storage = new ClassLikeStorage($fq_classlike_name);
+        $storage = new ClassLikeStorage($fq_classlike_name);
+        self::$storage[$fq_classlike_name_lc] = $storage;
+        self::$new_storage[$fq_classlike_name_lc] = $storage;
 
         return $storage;
     }
@@ -124,4 +141,12 @@ class ClassLikeStorageProvider
     {
         self::$storage = [];
     }
+
+    /**
+     * @return void
+     */
+    public static function populated()
+    {
+        self::$new_storage = [];
+    }
 }
diff --git a/src/Psalm/Provider/FileStorageProvider.php b/src/Psalm/Provider/FileStorageProvider.php
index 4ac74dccc..ec99e31ae 100644
--- a/src/Psalm/Provider/FileStorageProvider.php
+++ b/src/Psalm/Provider/FileStorageProvider.php
@@ -13,6 +13,14 @@ class FileStorageProvider
      */
     private static $storage = [];
 
+    /**
+     * A list of data useful to analyse new files
+     * Storing this statically is much faster (at least in PHP 7.2.1)
+     *
+     * @var array<string, FileStorage>
+     */
+    private static $new_storage = [];
+
     /**
      * @var ?FileStorageCacheProvider
      */
@@ -74,6 +82,7 @@ class FileStorageProvider
         }
 
         self::$storage[$file_path] = $cached_value;
+        self::$new_storage[$file_path] = $cached_value;
 
         return true;
     }
@@ -86,12 +95,21 @@ class FileStorageProvider
         return self::$storage;
     }
 
+    /**
+     * @return array<string, FileStorage>
+     */
+    public function getNew()
+    {
+        return self::$new_storage;
+    }
+
     /**
      * @param array<string, FileStorage> $more
      * @return void
      */
     public function addMore(array $more)
     {
+        self::$new_storage = array_merge($more, self::$new_storage);
         self::$storage = array_merge($more, self::$storage);
     }
 
@@ -104,7 +122,9 @@ class FileStorageProvider
     {
         $file_path_lc = strtolower($file_path);
 
-        self::$storage[$file_path_lc] = $storage = new FileStorage($file_path);
+        $storage = new FileStorage($file_path);
+        self::$storage[$file_path_lc] = $storage;
+        self::$new_storage[$file_path_lc] = $storage;
 
         return $storage;
     }
@@ -116,4 +136,12 @@ class FileStorageProvider
     {
         self::$storage = [];
     }
+
+    /**
+     * @return void
+     */
+    public static function populated()
+    {
+        self::$new_storage = [];
+    }
 }