diff --git a/bshell.runtime/include/bshell/runtime/runtime.h b/bshell.runtime/include/bshell/runtime/runtime.h
index b5c7841..16c6284 100644
--- a/bshell.runtime/include/bshell/runtime/runtime.h
+++ b/bshell.runtime/include/bshell/runtime/runtime.h
@@ -2,6 +2,7 @@
 #define BSHELL_RUNTIME_RUNTIME_H_
 
 #include <bshell/command/command.h>
+#include <bshell/command/function.h>
 #include <bshell/runtime/script-block.h>
 #include <bshell/runtime/var.h>
 #include <fx/collections/hashtable.h>
@@ -32,6 +33,9 @@ extern bshell_variable *bshell_runtime_find_var(
 extern bshell_variable *bshell_runtime_define_var(
 	struct bshell_runtime *rt,
 	const char *name);
+extern enum bshell_status bshell_runtime_define_function(
+	struct bshell_runtime *rt,
+	bshell_function *func);
 
 extern bshell_command *bshell_runtime_find_command(
 	struct bshell_runtime *rt,
diff --git a/bshell.runtime/include/bshell/runtime/var.h b/bshell.runtime/include/bshell/runtime/var.h
index b79e7ec..5005b3b 100644
--- a/bshell.runtime/include/bshell/runtime/var.h
+++ b/bshell.runtime/include/bshell/runtime/var.h
@@ -19,7 +19,7 @@ extern bshell_variable *bshell_variable_create(const char *name);
 
 extern const char *bshell_variable_get_name(const bshell_variable *var);
 extern const fx_value *bshell_variable_get_value(const bshell_variable *var);
-extern void bshell_variable_set_value(bshell_variable *var, fx_value *value);
+extern void bshell_variable_set_value(bshell_variable *var, fx_value value);
 
 FX_DECLS_END;
 
diff --git a/bshell.runtime/runtime/cmdcall.c b/bshell.runtime/runtime/cmdcall.c
index 3871b0a..61fa685 100644
--- a/bshell.runtime/runtime/cmdcall.c
+++ b/bshell.runtime/runtime/cmdcall.c
@@ -31,6 +31,11 @@ static void cmdcall_fini(fx_object *obj, void *priv)
 {
 	struct bshell_cmdcall_p *cmdcall = priv;
 
+	if (cmdcall->cmd_target) {
+		bshell_command_end_processing(cmdcall->cmd_target);
+		bshell_command_unref(cmdcall->cmd_target);
+	}
+
 	if (cmdcall->cmd_native_path) {
 		free(cmdcall->cmd_native_path);
 	}
@@ -44,11 +49,6 @@ static void cmdcall_fini(fx_object *obj, void *priv)
 	}
 
 	fx_vector_destroy(cmdcall->cmd_args, NULL);
-
-	if (cmdcall->cmd_target) {
-		bshell_command_end_processing(cmdcall->cmd_target);
-		bshell_command_unref(cmdcall->cmd_target);
-	}
 }
 
 static enum bshell_status cmdcall_push_arg(
diff --git a/bshell.runtime/runtime/eval.c b/bshell.runtime/runtime/eval.c
index 0979556..7415cbb 100644
--- a/bshell.runtime/runtime/eval.c
+++ b/bshell.runtime/runtime/eval.c
@@ -241,7 +241,7 @@ static enum bshell_status eval_instruction(
 		pool_value = bshell_scriptblock_get_pool_value(
 			scope->s_block,
 			arg,
-			FX_TYPE_CSTR);
+			FX_TYPE_STRING);
 		if (!pool_value) {
 			fprintf(stderr, "RUNTIME: invalid stlocal operand\n");
 			return BSHELL_ERR_BAD_SYNTAX;
@@ -253,7 +253,7 @@ static enum bshell_status eval_instruction(
 			var = bshell_runtime_define_var(rt, s);
 		}
 
-		bshell_variable_set_value(var, &x);
+		bshell_variable_set_value(var, x);
 		bshell_runtime_scope_push_value(scope, &x);
 		fx_value_unset(&x);
 		break;
@@ -314,7 +314,8 @@ static enum bshell_status eval_instruction(
 		bshell_cmdcall *result = bshell_cmdcall_create();
 
 		while (arg > 0) {
-			fx_value cmd_arg = bshell_runtime_scope_pop_value(scope);
+			fx_value cmd_arg
+				= bshell_runtime_scope_pop_value(scope);
 			bshell_cmdcall_push_arg(result, cmd_arg);
 			fx_value_unset(&cmd_arg);
 			arg--;
@@ -322,6 +323,7 @@ static enum bshell_status eval_instruction(
 
 		bstatus = bshell_cmdcall_resolve(result, rt);
 		if (bstatus != BSHELL_SUCCESS) {
+			bshell_cmdcall_unref(result);
 			break;
 		}
 
@@ -422,7 +424,9 @@ fx_value bshell_runtime_eval_global(
 {
 	enum bshell_status status = BSHELL_SUCCESS;
 	bshell_runtime_scope_set_block(rt->rt_global, block);
-	return runtime_eval(rt);
+	fx_value result = runtime_eval(rt);
+	bshell_runtime_scope_set_block(rt->rt_global, NULL);
+	return result;
 }
 
 fx_value bshell_runtime_eval_script(
diff --git a/bshell.runtime/runtime/pipeline.c b/bshell.runtime/runtime/pipeline.c
index dc41c1b..1edcbec 100644
--- a/bshell.runtime/runtime/pipeline.c
+++ b/bshell.runtime/runtime/pipeline.c
@@ -26,6 +26,7 @@ static void pipeline_fini(fx_object *obj, void *priv)
 	for (size_t i = 0; i < pipeline->p_cmds.count; i++) {
 		bshell_cmdcall_unref(pipeline->p_cmds.items[i]);
 	}
+	fx_vector_destroy(pipeline->p_cmds, NULL);
 
 	if (pipeline->p_in) {
 		fx_array_unref(pipeline->p_in);
diff --git a/bshell.runtime/runtime/runtime.c b/bshell.runtime/runtime/runtime.c
index 351c2c3..27eef01 100644
--- a/bshell.runtime/runtime/runtime.c
+++ b/bshell.runtime/runtime/runtime.c
@@ -21,6 +21,10 @@ struct bshell_runtime *bshell_runtime_create(void)
 
 void bshell_runtime_destroy(struct bshell_runtime *rt)
 {
+	while (!fx_queue_empty(&rt->rt_scope)) {
+		runtime_pop_scope(rt);
+	}
+
 	fx_hashtable_unref(rt->rt_aliases);
 	free(rt);
 }
@@ -63,6 +67,31 @@ bshell_variable *bshell_runtime_define_var(
 	return var;
 }
 
+enum bshell_status bshell_runtime_define_function(
+	struct bshell_runtime *rt,
+	bshell_function *func)
+{
+	struct bshell_runtime_scope *scope = runtime_get_scope(rt);
+	if (!scope) {
+		return BSHELL_ERR_BAD_STATE;
+	}
+
+	fx_string *name
+		= fx_string_create_from_cstr(bshell_function_get_name(func));
+	if (!name) {
+		return BSHELL_ERR_NO_MEMORY;
+	}
+
+	fx_string_transform_lowercase(name);
+	fx_hashtable_put(
+		scope->s_functions,
+		&FX_VALUE_OBJECT(name),
+		&FX_VALUE_OBJECT(func));
+	fx_string_unref(name);
+
+	return BSHELL_SUCCESS;
+}
+
 bshell_command *bshell_runtime_find_command(
 	struct bshell_runtime *rt,
 	const char *callable_name)
diff --git a/bshell.runtime/runtime/scope.c b/bshell.runtime/runtime/scope.c
index 682a362..b3b0dc2 100644
--- a/bshell.runtime/runtime/scope.c
+++ b/bshell.runtime/runtime/scope.c
@@ -37,7 +37,14 @@ void runtime_pop_scope(struct bshell_runtime *rt)
 
 	struct bshell_runtime_scope *scope
 		= fx_unbox(struct bshell_runtime_scope, entry, s_entry);
-	/* TODO */
+
+	if (scope->s_block) {
+		bshell_scriptblock_unref(scope->s_block);
+	}
+
+	fx_value_unset_array(scope->s_stack.items, scope->s_stack.count);
+	var_map_cleanup(&scope->s_vars);
+	fx_vector_destroy(scope->s_stack, NULL);
 	fx_hashtable_unref(scope->s_functions);
 	free(scope);
 }
@@ -79,7 +86,11 @@ void bshell_runtime_scope_set_block(
 	struct bshell_runtime_scope *scope,
 	bshell_scriptblock *block)
 {
-	scope->s_block = block;
+	if (scope->s_block) {
+		bshell_scriptblock_unref(scope->s_block);
+	}
+
+	scope->s_block = bshell_scriptblock_ref(block);
 	scope->s_ip = 0;
 	bshell_scriptblock_get_text(block, &scope->s_instr, &scope->s_nr_instr);
 	bshell_scriptblock_get_pool(block, &scope->s_pool, &scope->s_nr_pool);
diff --git a/bshell.runtime/runtime/var-map.c b/bshell.runtime/runtime/var-map.c
index 55a3cde..0f5e321 100644
--- a/bshell.runtime/runtime/var-map.c
+++ b/bshell.runtime/runtime/var-map.c
@@ -1,7 +1,16 @@
 #include "var-map.h"
 
+static void var_entry_cleanup(fx_namemap_entry *entry)
+{
+	struct var_map_entry *map_entry
+		= fx_unbox(struct var_map_entry, entry, e_entry);
+	bshell_variable_unref(map_entry->e_var);
+	free(map_entry);
+}
+
 void var_map_cleanup(struct var_map *map)
 {
+	fx_namemap_cleanup(&map->m_vars, var_entry_cleanup);
 }
 
 enum bshell_status var_map_put(struct var_map *map, bshell_variable *var)
@@ -27,9 +36,7 @@ bshell_variable *var_map_get(struct var_map *map, const char *name)
 		return NULL;
 	}
 
-	struct var_map_entry *entry = fx_unbox(
-		struct var_map_entry,
-		e,
-		e_entry);
+	struct var_map_entry *entry
+		= fx_unbox(struct var_map_entry, e, e_entry);
 	return entry->e_var;
 }
diff --git a/bshell.runtime/runtime/var.c b/bshell.runtime/runtime/var.c
index 0a12868..66b8a7f 100644
--- a/bshell.runtime/runtime/var.c
+++ b/bshell.runtime/runtime/var.c
@@ -29,10 +29,10 @@ static const fx_value *variable_get_value(const struct bshell_variable_p *var)
 	return &var->var_value;
 }
 
-static void variable_set_value(struct bshell_variable_p *var, fx_value *value)
+static void variable_set_value(struct bshell_variable_p *var, fx_value value)
 {
 	fx_value_unset(&var->var_value);
-	fx_value_copy(&var->var_value, value);
+	var->var_value = fx_value_copy_return(value);
 }
 
 bshell_variable *bshell_variable_create(const char *name)
@@ -70,7 +70,7 @@ const fx_value *bshell_variable_get_value(const bshell_variable *var)
 		var);
 }
 
-void bshell_variable_set_value(bshell_variable *var, fx_value *value)
+void bshell_variable_set_value(bshell_variable *var, fx_value value)
 {
 	FX_CLASS_DISPATCH_STATIC_V(
 		BSHELL_TYPE_VARIABLE,