diff --git a/integration_tests/CMakeLists.txt b/integration_tests/CMakeLists.txt
index d5a477f006..b0dac2be81 100644
--- a/integration_tests/CMakeLists.txt
+++ b/integration_tests/CMakeLists.txt
@@ -717,7 +717,7 @@ RUN(NAME symbolics_10        LABELS cpython_sym c_sym llvm_sym NOFAST)
 RUN(NAME symbolics_11        LABELS cpython_sym c_sym llvm_sym NOFAST)
 RUN(NAME symbolics_12        LABELS cpython_sym c_sym llvm_sym NOFAST)
 RUN(NAME symbolics_13        LABELS cpython_sym c_sym llvm_sym NOFAST)
-RUN(NAME test_gruntz         LABELS cpython_sym llvm_sym NOFAST)
+RUN(NAME test_gruntz         LABELS cpython_sym c_sym llvm_sym NOFAST)
 
 RUN(NAME sizeof_01           LABELS llvm c
         EXTRAFILES sizeof_01b.c)
diff --git a/src/libasr/codegen/asr_to_c.cpp b/src/libasr/codegen/asr_to_c.cpp
index c39fc2990f..bae0a5e7d4 100644
--- a/src/libasr/codegen/asr_to_c.cpp
+++ b/src/libasr/codegen/asr_to_c.cpp
@@ -415,11 +415,6 @@ class ASRToCVisitor : public BaseCCPPVisitor<ASRToCVisitor>
                 headers.insert("complex.h");
                 convert_variable_decl_util(v, is_array, declare_as_constant, use_ref, dummy,
                     force_declare, force_declare_name, n_dims, m_dims, v_m_type, dims, sub);
-            } else if (ASR::is_a<ASR::SymbolicExpression_t>(*v_m_type)) {
-                headers.insert("symengine/cwrapper.h");
-                std::string type_name = "basic";
-                std::string v_m_name = v.m_name;
-                sub = format_type_c("", type_name, v_m_name, use_ref, dummy);
             } else if (ASRUtils::is_logical(*v_m_type)) {
                 convert_variable_decl_util(v, is_array, declare_as_constant, use_ref, dummy,
                     force_declare, force_declare_name, n_dims, m_dims, v_m_type, dims, sub);
@@ -529,7 +524,12 @@ class ASRToCVisitor : public BaseCCPPVisitor<ASRToCVisitor>
             } else if (ASR::is_a<ASR::List_t>(*v_m_type)) {
                 ASR::List_t* t = ASR::down_cast<ASR::List_t>(v_m_type);
                 std::string list_type_c = c_ds_api->get_list_type(t);
-                sub = format_type_c("", list_type_c, v.m_name,
+                std::string name = v.m_name;
+                if (name == "_lpython_return_variable" && v.m_intent == ASRUtils::intent_out) {
+                    is_return_var_intent_out = true;
+                    name = "*" + name;
+                }
+                sub = format_type_c("", list_type_c, name,
                                     false, false);
             } else if (ASR::is_a<ASR::Tuple_t>(*v_m_type)) {
                 ASR::Tuple_t* t = ASR::down_cast<ASR::Tuple_t>(v_m_type);
diff --git a/src/libasr/codegen/asr_to_c_cpp.h b/src/libasr/codegen/asr_to_c_cpp.h
index e7dbd05a3f..89874c9677 100644
--- a/src/libasr/codegen/asr_to_c_cpp.h
+++ b/src/libasr/codegen/asr_to_c_cpp.h
@@ -148,6 +148,8 @@ class BaseCCPPVisitor : public ASR::BaseVisitor<Struct>
     SymbolTable* current_scope;
     bool is_string_concat_present;
 
+    bool is_return_var_intent_out = false;
+
     BaseCCPPVisitor(diag::Diagnostics &diag, Platform &platform,
             CompilerOptions &_compiler_options, bool gen_stdstring, bool gen_stdcomplex, bool is_c,
             int64_t default_lower_bound) : diag{diag},
@@ -1077,6 +1079,16 @@ PyMODINIT_FUNC PyInit_lpython_module_)" + fn_name + R"((void) {
                     || param->m_intent == ASRUtils::intent_out)
                     && !ASRUtils::is_aggregate_type(param->m_type))) {
                     args += "&" + src;
+                } else if (std::string(param->m_name) == "_lpython_return_variable"
+                    && param->m_intent == ASRUtils::intent_out) {
+                    if (ASR::is_a<ASR::List_t>(*param->m_type)) {
+                        ASR::List_t* list_type = ASR::down_cast<ASR::List_t>(param->m_type);
+                        if (list_type->m_type->type == ASR::ttypeType::CPtr){
+                            args += "&" + src;
+                        }
+                    } else {
+                        args += src;
+                    }
                 } else {
                     args += src;
                 }
@@ -1367,7 +1379,12 @@ PyMODINIT_FUNC PyInit_lpython_module_)" + fn_name + R"((void) {
         if( is_target_list && is_value_list ) {
             ASR::List_t* list_target = ASR::down_cast<ASR::List_t>(ASRUtils::expr_type(x.m_target));
             std::string list_dc_func = c_ds_api->get_list_deepcopy_func(list_target);
-            src += indent + list_dc_func + "(&" + value + ", &" + target + ");\n\n";
+            if (target == "_lpython_return_variable" && is_return_var_intent_out) {
+                src += indent + list_dc_func + "(&" + value + ", " + target + ");\n\n";
+                is_return_var_intent_out = false;
+            } else {
+                src += indent + list_dc_func + "(&" + value + ", &" + target + ");\n\n";
+            }
         } else if ( is_target_tup && is_value_tup ) {
             ASR::Tuple_t* tup_target = ASR::down_cast<ASR::Tuple_t>(ASRUtils::expr_type(x.m_target));
             std::string dc_func = c_ds_api->get_tuple_deepcopy_func(tup_target);