diff --git a/src/Illuminate/Database/Eloquent/Concerns/QueriesRelationships.php b/src/Illuminate/Database/Eloquent/Concerns/QueriesRelationships.php
index 289770375f94..5f2ec2dab7b9 100644
--- a/src/Illuminate/Database/Eloquent/Concerns/QueriesRelationships.php
+++ b/src/Illuminate/Database/Eloquent/Concerns/QueriesRelationships.php
@@ -210,14 +210,18 @@ public function withCount($relations)
 
             $query->callScope($constraints);
 
-            $query->mergeConstraintsFrom($relation->getQuery());
+            $query = $query->mergeConstraintsFrom($relation->getQuery())->toBase();
+
+            if (count($query->columns) > 1) {
+                $query->columns = [$query->columns[0]];
+            }
 
             // Finally we will add the proper result column alias to the query and run the subselect
             // statement against the query builder. Then we will return the builder instance back
             // to the developer for further constraint chaining that needs to take place on it.
             $column = $alias ?? Str::snake($name.'_count');
 
-            $this->selectSub($query->toBase(), $column);
+            $this->selectSub($query, $column);
         }
 
         return $this;
diff --git a/src/Illuminate/Database/Query/Builder.php b/src/Illuminate/Database/Query/Builder.php
index 2bbddfd066f9..1025915ed919 100755
--- a/src/Illuminate/Database/Query/Builder.php
+++ b/src/Illuminate/Database/Query/Builder.php
@@ -279,8 +279,6 @@ public function selectSub($query, $as)
     protected function parseSubSelect($query)
     {
         if ($query instanceof self) {
-            $query->columns = [$query->columns[0]];
-
             return [$query->toSql(), $query->getBindings()];
         } elseif (is_string($query)) {
             return [$query, []];
diff --git a/tests/Database/DatabaseQueryBuilderTest.php b/tests/Database/DatabaseQueryBuilderTest.php
index 49d514b6bd67..02ca507f9f38 100755
--- a/tests/Database/DatabaseQueryBuilderTest.php
+++ b/tests/Database/DatabaseQueryBuilderTest.php
@@ -1449,10 +1449,11 @@ public function testAggregateWithSubSelect()
             return $results;
         });
         $builder->from('users')->selectSub(function ($query) {
-            $query->from('posts')->select('foo')->where('title', 'foo');
+            $query->from('posts')->select('foo', 'bar')->where('title', 'foo');
         }, 'post');
         $count = $builder->count();
         $this->assertEquals(1, $count);
+        $this->assertEquals('(select "foo", "bar" from "posts" where "title" = ?) as "post"', $builder->columns[0]->getValue());
         $this->assertEquals(['foo'], $builder->getBindings());
     }