diff --git a/hawk/lib/mod-sys.c b/hawk/lib/mod-sys.c
index 7e64c38f..085f0dd6 100644
--- a/hawk/lib/mod-sys.c
+++ b/hawk/lib/mod-sys.c
@@ -3223,7 +3223,6 @@ static int fnc_utime (hawk_rtx_t* rtx, const hawk_fnc_info_t* fi)
 
 static int fnc_openmux (hawk_rtx_t* rtx, const hawk_fnc_info_t* fi)
 {
-#if defined(USE_EPOLL)
 	sys_list_t* sys_list;
 	sys_node_t* sys_node = HAWK_NULL;
 	hawk_int_t rx;
@@ -3248,9 +3247,6 @@ static int fnc_openmux (hawk_rtx_t* rtx, const hawk_fnc_info_t* fi)
 		}
 		#endif
 	}
-#else
-	/* TODO: */
-#endif
 
 	if (fd >= 0)
 	{
@@ -3269,19 +3265,17 @@ static int fnc_openmux (hawk_rtx_t* rtx, const hawk_fnc_info_t* fi)
 	{
 		rx = set_error_on_sys_list_with_errno(rtx, sys_list, HAWK_NULL);
 	}
+#else
+	rx = set_error_on_sys_list(rtx, sys_list, HAWK_ENOIMPL, HAWK_NULL);
+#endif
 
 	/*HAWK_ASSERT (HAWK_IN_QUICKINT_RANGE(rx));*/
 	hawk_rtx_setretval (rtx, hawk_rtx_makeintval(rtx, rx));
 	return 0;
-#else
-	hawk_rtx_setretval (rtx, hawk_rtx_makeintval(rtx, ERRNUM_TO_RC(HAWK_ENOIMPL)));
-	return 0;
-#endif
 }
 
 static int fnc_closemux (hawk_rtx_t* rtx, const hawk_fnc_info_t* fi)
 {
-#if defined(USE_EPOLL)
 	sys_list_t* sys_list;
 	sys_node_t* sys_node;
 	hawk_int_t rx = ERRNUM_TO_RC(HAWK_ENOERR);
@@ -3293,10 +3287,6 @@ static int fnc_closemux (hawk_rtx_t* rtx, const hawk_fnc_info_t* fi)
 
 	hawk_rtx_setretval (rtx, hawk_rtx_makeintval(rtx, rx));
 	return 0;
-#else
-	hawk_rtx_setretval (rtx, hawk_rtx_makeintval(rtx, ERRNUM_TO_RC(HAWK_ENOIMPL)));
-	return 0;
-#endif
 }
 
 #if defined(USE_EPOLL)
diff --git a/hawk/lib/run.c b/hawk/lib/run.c
index 41e66d36..8d5d35e7 100644
--- a/hawk/lib/run.c
+++ b/hawk/lib/run.c
@@ -1680,7 +1680,7 @@ hawk_val_t* hawk_rtx_execwithucstrarr (hawk_rtx_t* rtx, const hawk_uch_t* args[]
 #if defined(HAWK_ENABLE_GC)
 	/* i assume this function is a usual hawk program starter.
 	 * call garbage collection after a whole program finishes */
-	//hawk_rtx_gc (rtx);
+	hawk_rtx_gc (rtx);
 #endif
 
 	return v;
@@ -1697,7 +1697,7 @@ hawk_val_t* hawk_rtx_execwithbcstrarr (hawk_rtx_t* rtx, const hawk_bch_t* args[]
 #if defined(HAWK_ENABLE_GC)
 	/* i assume this function is a usual hawk program starter.
 	 * call garbage collection after a whole program finishes */
-	//hawk_rtx_gc (rtx);
+	hawk_rtx_gc (rtx);
 #endif
 
 	return v;
diff --git a/hawk/scripts/generrcode.awk b/hawk/scripts/generrcode.hawk
similarity index 90%
rename from hawk/scripts/generrcode.awk
rename to hawk/scripts/generrcode.hawk
index 2c672971..1ec1ead4 100644
--- a/hawk/scripts/generrcode.awk
+++ b/hawk/scripts/generrcode.hawk
@@ -1,7 +1,7 @@
 #
-# generrcode.awk
+# generrcode.hawk
 #
-# hawk -f generrcode.awk hawk-cmn.h
+# hawk -f generrcode.hawk hawk-cmn.h
 #
 
 BEGIN { 
diff --git a/hawk/scripts/genoptcode.awk b/hawk/scripts/genoptcode.hawk
similarity index 90%
rename from hawk/scripts/genoptcode.awk
rename to hawk/scripts/genoptcode.hawk
index a460c4d4..463ca73e 100644
--- a/hawk/scripts/genoptcode.awk
+++ b/hawk/scripts/genoptcode.hawk
@@ -1,7 +1,7 @@
 #
-# genoptcode.awk
+# genoptcode.hawk
 #
-# hawk -f genoptcode.awk hawk.h
+# hawk -f genoptcode.hawk hawk.h
 #
 
 BEGIN { 
diff --git a/hawk/scripts/tcp-proxy.awk b/hawk/scripts/tcp-proxy.hawk
similarity index 100%
rename from hawk/scripts/tcp-proxy.awk
rename to hawk/scripts/tcp-proxy.hawk