diff --git a/lib/am.c b/lib/am.c
index acf203b..cf32605 100644
--- a/lib/am.c
+++ b/lib/am.c
@@ -14,16 +14,16 @@ void am_init(am_t *am)
 	env_init(am);
 }
 
-void am_push(am_t *am)
+void am_push(am_t *am, am_reg_t reg)
 {
 	assert(am->sp >= am->stack);
-	*am->sp-- = AM_EXPR(am);
+	*am->sp-- = am->regs[reg];
 }
 
-void am_pop(am_t *am)
+void am_pop(am_t *am, am_reg_t reg)
 {
 	assert(am->sp < am->stack + AM_STACK_SIZE - 1);
-	AM_EXPR(am) = *++am->sp;
+	am->regs[reg] = *++am->sp;
 }
 
 void am_append_arg(am_t *am)
diff --git a/lib/eval.c b/lib/eval.c
index e6eebb8..386a4a2 100644
--- a/lib/eval.c
+++ b/lib/eval.c
@@ -25,22 +25,19 @@ static void eval_list(am_t *am)
 	AM_EXPR(am) = AM_EXPR(am)->pair.car;
 
 	while (!AM_UNEV(am)->is_atom) {
-		am_push(am);
+		am_push(am, EXPR);
 		AM_EXPR(am) = AM_UNEV(am)->pair.cdr;
-		am_push(am);
-		AM_EXPR(am) = AM_ARGL(am);
-		am_push(am);
+		am_push(am, EXPR);
+		am_push(am, ARGL);
 
 		AM_EXPR(am) = AM_UNEV(am)->pair.car;
 		eval(am);
 
-		am_pop(am);
-		AM_ARGL(am) = AM_EXPR(am);
+		am_pop(am, ARGL);
 		am_append_arg(am);
 
-		am_pop(am);
-		AM_UNEV(am) = AM_EXPR(am);
-		am_pop(am);
+		am_pop(am, UNEV);
+		am_pop(am, EXPR);
 	}
 
 	assert(AM_EXPR(am)->is_atom);
diff --git a/lib/include/am.h b/lib/include/am.h
index 8cd4d38..36240f0 100644
--- a/lib/include/am.h
+++ b/lib/include/am.h
@@ -29,8 +29,8 @@ typedef struct am {
 } am_t;
 
 void am_init(am_t *am);
-void am_push(am_t *am);
-void am_pop(am_t *am);
+void am_push(am_t *am, am_reg_t reg);
+void am_pop(am_t *am, am_reg_t reg);
 void am_append_arg(am_t *am);
 
 #endif
diff --git a/lib/parse.c b/lib/parse.c
index d8f103d..7622485 100644
--- a/lib/parse.c
+++ b/lib/parse.c
@@ -67,7 +67,7 @@ parse_state_t parse_proc(parse_ctx_t *ctx, const token_t *token)
 			append(ctx, expr_symbol(ctx->am, &token->symbol));
 			break;
 		case TOKEN_TYPE_OPEN_PAREN:
-			am_push(ctx->am);
+			am_push(ctx->am, EXPR);
 			push_state(ctx, PARSE_STATE_LIST);
 			AM_EXPR(ctx->am) = expr_empty_list(ctx->am);
 			ctx->state = PARSE_STATE_LIST;
@@ -76,7 +76,7 @@ parse_state_t parse_proc(parse_ctx_t *ctx, const token_t *token)
 			ctx->state = pop_state(ctx);
 			if (ctx->state == PARSE_STATE_LIST) {
 				expr_t *expr = AM_EXPR(ctx->am);
-				am_pop(ctx->am);
+				am_pop(ctx->am, EXPR);
 				append(ctx, expr);
 			}
 			break;
diff --git a/tests/am_tests.c b/tests/am_tests.c
index dba4004..06ac962 100644
--- a/tests/am_tests.c
+++ b/tests/am_tests.c
@@ -20,13 +20,25 @@ static void test_expr_value_restored_after_push_modify_pop(void)
 	expr_t a, b;
 
 	am.regs[EXPR] = &a;
-	am_push(&am);
+	am_push(&am, EXPR);
 	am.regs[EXPR] = &b;
-	am_pop(&am);
+	am_pop(&am, EXPR);
 
 	TEST_ASSERT_EQUAL(&a, am.regs[EXPR]);
 }
 
+static void test_argl_value_restored_after_push_modify_pop(void)
+{
+	expr_t a, b;
+
+	am.regs[ARGL] = &a;
+	am_push(&am, ARGL);
+	am.regs[ARGL] = &b;
+	am_pop(&am, ARGL);
+
+	TEST_ASSERT_EQUAL(&a, am.regs[ARGL]);
+}
+
 static void test_append_arg_42_with_empty_argl(void)
 {
 	am.regs[ARGL] = expr_empty_list(&am);
@@ -48,6 +60,7 @@ int main(void)
 {
 	UNITY_BEGIN();
 	RUN_TEST(test_expr_value_restored_after_push_modify_pop);
+	RUN_TEST(test_argl_value_restored_after_push_modify_pop);
 	RUN_TEST(test_append_arg_42_with_empty_argl);
 	return UNITY_END();
 }