diff --git a/src/collections_methods.c b/src/collections_methods.c
index 0b0355b..2814ce1 100644
--- a/src/collections_methods.c
+++ b/src/collections_methods.c
@@ -308,9 +308,9 @@ PHP_METHOD(Collection, associateBy)
 
 PHP_METHOD(Collection, associateByTo)
 {
+    zval* dest;
     zend_fcall_info fci;
     zend_fcall_info_cache fcc;
-    zval* dest;
     ZEND_PARSE_PARAMETERS_START(2, 2)
         Z_PARAM_OBJECT_OF_CLASS(dest, collections_collection_ce)
         Z_PARAM_FUNC(fci, fcc)
@@ -635,12 +635,48 @@ PHP_METHOD(Collection, filterNot)
 
 PHP_METHOD(Collection, filterNotTo)
 {
-    
+    zval* dest;
+    zend_fcall_info fci;
+    zend_fcall_info_cache fcc;
+    ZEND_PARSE_PARAMETERS_START(2, 2)
+        Z_PARAM_OBJECT_OF_CLASS(dest, collections_collection_ce)
+        Z_PARAM_FUNC(fci, fcc)
+    ZEND_PARSE_PARAMETERS_END();
+    INIT_FCI();
+    zval* current = COLLECTION_FETCH_EX();
+    zend_array* dest_arr = Z_ARRVAL_P(COLLECTION_FETCH(dest));
+    ZEND_HASH_FOREACH_BUCKET(Z_ARRVAL_P(current), Bucket* bucket)
+        CALLBACK_KEYVAL_INVOKE(params, bucket);
+        if (!zend_is_true(&retval))
+            if (bucket->key)
+                zend_hash_add(dest_arr, bucket->key, &bucket->val);
+            else
+                zend_hash_next_index_insert(dest_arr, &bucket->val);
+    ZEND_HASH_FOREACH_END();
+    RETVAL_ZVAL(dest, 1, 0);
 }
 
 PHP_METHOD(Collection, filterTo)
 {
-    
+    zval* dest;
+    zend_fcall_info fci;
+    zend_fcall_info_cache fcc;
+    ZEND_PARSE_PARAMETERS_START(2, 2)
+        Z_PARAM_OBJECT_OF_CLASS(dest, collections_collection_ce)
+        Z_PARAM_FUNC(fci, fcc)
+    ZEND_PARSE_PARAMETERS_END();
+    INIT_FCI();
+    zval* current = COLLECTION_FETCH_EX();
+    zend_array* dest_arr = Z_ARRVAL_P(COLLECTION_FETCH(dest));
+    ZEND_HASH_FOREACH_BUCKET(Z_ARRVAL_P(current), Bucket* bucket)
+        CALLBACK_KEYVAL_INVOKE(params, bucket);
+        if (zend_is_true(&retval))
+            if (bucket->key)
+                zend_hash_add(dest_arr, bucket->key, &bucket->val);
+            else
+                zend_hash_next_index_insert(dest_arr, &bucket->val);
+    ZEND_HASH_FOREACH_END();
+    RETVAL_ZVAL(dest, 1, 0);
 }
 
 PHP_METHOD(Collection, find)
diff --git a/tests/017-filter.phpt b/tests/017-filter.phpt
index 6c7b53c..6350ccb 100644
--- a/tests/017-filter.phpt
+++ b/tests/017-filter.phpt
@@ -1,5 +1,5 @@
 --TEST--
-Test Collection::filter() and Collection::filterNot().
+Test Collection::filter(), Collection::filterNot(), Collection::filterTo(), Collection::filterNotTo().
 --FILE--
 <?php
 $array = [1, 3, 4, 5, 8, 10, 13];
@@ -14,6 +14,13 @@ $collection1 = Collection::init($array)->filterNot($pred_is_odd);
 if ($collection->toArray() != array_filter($array, $pred_is_odd))
     echo 'Collection::filter() failed.', PHP_EOL;
 if ($collection1->toArray() != array_filter($array, $pred_is_even))
-    echo 'Collection::filter() failed.', PHP_EOL;
+    echo 'Collection::filterNot() failed.', PHP_EOL;
+$dest = Collection::init($array);
+$collection2 = Collection::init($array)->filterTo($dest, $pred_is_odd);
+if ($collection2->toArray() != array_merge($array, $collection->toArray()))
+    echo 'Collection::filterTo() failed.', PHP_EOL;
+$collection3 = Collection::init($array)->filterNotTo($dest, $pred_is_odd);
+if ($collection3->toArray() != array_merge($array, $collection->toArray(), $collection1->toArray()))
+    echo 'Collection::filterNotTo() failed.', PHP_EOL;
 ?>
 --EXPECT--