diff --git a/src/Illuminate/Database/Query/Builder.php b/src/Illuminate/Database/Query/Builder.php
index 929ec0180c3f..a1eb420e6e7b 100755
--- a/src/Illuminate/Database/Query/Builder.php
+++ b/src/Illuminate/Database/Query/Builder.php
@@ -1686,11 +1686,11 @@ public function max($column)
      * Retrieve the sum of the values of a given column.
      *
      * @param  string  $column
-     * @return mixed
+     * @return float|int
      */
     public function sum($column)
     {
-        return $this->aggregate(__FUNCTION__, [$column]);
+        return $this->numericAggregate(__FUNCTION__, [$column]);
     }
 
     /**
diff --git a/tests/Database/DatabaseQueryBuilderTest.php b/tests/Database/DatabaseQueryBuilderTest.php
index 1c16c6d85dab..ae9bc8bd8e53 100755
--- a/tests/Database/DatabaseQueryBuilderTest.php
+++ b/tests/Database/DatabaseQueryBuilderTest.php
@@ -883,7 +883,7 @@ public function testAggregateFunctions()
             return $results;
         });
         $results = $builder->from('users')->sum('id');
-        $this->assertEquals(1, $results);
+        $this->assertSame(1, $results);
     }
 
     public function testSqlServerExists()