diff --git a/integration_tests/class_06.py b/integration_tests/class_06.py
index 981c75910c..8f9d71b35f 100644
--- a/integration_tests/class_06.py
+++ b/integration_tests/class_06.py
@@ -6,11 +6,13 @@ def __init__(self:"Base"):
 class Derived(Base):
     pass
 
-def f(i:Base):
+def f(i:Base) -> i32:
     print(i.x)
+    return i.x
 
 def main():
     d : Derived = Derived()
-    f(d)
+    op :i32 = f(d)
+    assert op == 10
 
 main()
diff --git a/tests/reference/asr-class_06-cdc5e29.json b/tests/reference/asr-class_06-cdc5e29.json
index b8577a9ed0..e22d71d362 100644
--- a/tests/reference/asr-class_06-cdc5e29.json
+++ b/tests/reference/asr-class_06-cdc5e29.json
@@ -2,11 +2,11 @@
     "basename": "asr-class_06-cdc5e29",
     "cmd": "lpython --show-asr --no-color {infile} -o {outfile}",
     "infile": "tests/../integration_tests/class_06.py",
-    "infile_hash": "f6ac8d14e8dcd9e828294fdc9fa65f930eb30e65094f342cd296cfb2",
+    "infile_hash": "14c2deb888846d507958aaff8cca0de9ebb3514eb91e631ee38db582",
     "outfile": null,
     "outfile_hash": null,
     "stdout": "asr-class_06-cdc5e29.stdout",
-    "stdout_hash": "26981374520cb1e14bfbc5b2fb349c66200d649a9f35bb110fc64287",
+    "stdout_hash": "c91e6e81e2ebbaf0d641e42fad2056b6069db42c53f1ed7a8b442b47",
     "stderr": null,
     "stderr_hash": null,
     "returncode": 0
diff --git a/tests/reference/asr-class_06-cdc5e29.stdout b/tests/reference/asr-class_06-cdc5e29.stdout
index 62e1645a79..367efc3c11 100644
--- a/tests/reference/asr-class_06-cdc5e29.stdout
+++ b/tests/reference/asr-class_06-cdc5e29.stdout
@@ -178,6 +178,22 @@
                                     (SymbolTable
                                         6
                                         {
+                                            _lpython_return_variable:
+                                                (Variable
+                                                    6
+                                                    _lpython_return_variable
+                                                    []
+                                                    ReturnVar
+                                                    ()
+                                                    ()
+                                                    Default
+                                                    (Integer 4)
+                                                    ()
+                                                    Source
+                                                    Public
+                                                    Required
+                                                    .false.
+                                                ),
                                             i:
                                                 (Variable
                                                     6
@@ -238,7 +254,7 @@
                                             .false.
                                             2 Base
                                         )]
-                                        ()
+                                        (Integer 4)
                                         Source
                                         Implementation
                                         ()
@@ -261,8 +277,19 @@
                                         )]
                                         ()
                                         ()
-                                    )]
-                                    ()
+                                    )
+                                    (Assignment
+                                        (Var 6 _lpython_return_variable)
+                                        (StructInstanceMember
+                                            (Var 6 i)
+                                            3 x
+                                            (Integer 4)
+                                            ()
+                                        )
+                                        ()
+                                    )
+                                    (Return)]
+                                    (Var 6 _lpython_return_variable)
                                     Public
                                     .false.
                                     .false.
@@ -293,6 +320,22 @@
                                                     Public
                                                     Required
                                                     .false.
+                                                ),
+                                            op:
+                                                (Variable
+                                                    7
+                                                    op
+                                                    []
+                                                    Local
+                                                    ()
+                                                    ()
+                                                    Default
+                                                    (Integer 4)
+                                                    ()
+                                                    Source
+                                                    Public
+                                                    Required
+                                                    .false.
                                                 )
                                         })
                                     main
@@ -327,35 +370,51 @@
                                         )
                                         ()
                                     )
-                                    (SubroutineCall
-                                        2 f
-                                        ()
-                                        [((Cast
-                                            (Var 7 d)
-                                            DerivedToBase
-                                            (StructType
-                                                [(Integer 4)]
-                                                [(FunctionType
-                                                    [(Class
-                                                        2 Base
+                                    (Assignment
+                                        (Var 7 op)
+                                        (FunctionCall
+                                            2 f
+                                            ()
+                                            [((Cast
+                                                (Var 7 d)
+                                                DerivedToBase
+                                                (StructType
+                                                    [(Integer 4)]
+                                                    [(FunctionType
+                                                        [(Class
+                                                            2 Base
+                                                        )]
+                                                        ()
+                                                        Source
+                                                        Implementation
+                                                        ()
+                                                        .false.
+                                                        .false.
+                                                        .false.
+                                                        .false.
+                                                        .false.
+                                                        []
+                                                        .false.
                                                     )]
-                                                    ()
-                                                    Source
-                                                    Implementation
-                                                    ()
                                                     .false.
-                                                    .false.
-                                                    .false.
-                                                    .false.
-                                                    .false.
-                                                    []
-                                                    .false.
-                                                )]
-                                                .false.
-                                                2 Base
-                                            )
+                                                    2 Base
+                                                )
+                                                ()
+                                            ))]
+                                            (Integer 4)
                                             ()
-                                        ))]
+                                            ()
+                                        )
+                                        ()
+                                    )
+                                    (Assert
+                                        (IntegerCompare
+                                            (Var 7 op)
+                                            Eq
+                                            (IntegerConstant 10 (Integer 4))
+                                            (Logical 4)
+                                            ()
+                                        )
                                         ()
                                     )]
                                     ()