diff --git a/arch/lkl/defconfig b/arch/lkl/defconfig
index f91380beee7c..060016840df4 100644
--- a/arch/lkl/defconfig
+++ b/arch/lkl/defconfig
@@ -31,8 +31,8 @@ CONFIG_EXT4_FS_POSIX_ACL=y
 CONFIG_EXT4_FS_SECURITY=y
 CONFIG_XFS_FS=y
 CONFIG_XFS_POSIX_ACL=y
-CONFIG_BTRFS_FS=y
-CONFIG_BTRFS_FS_POSIX_ACL=y
+#CONFIG_BTRFS_FS=y
+#CONFIG_BTRFS_FS_POSIX_ACL=y
 # CONFIG_FILE_LOCKING is not set
 # CONFIG_DNOTIFY is not set
 # CONFIG_INOTIFY_USER is not set
diff --git a/tools/lkl/Makefile.autoconf b/tools/lkl/Makefile.autoconf
index 77421d91de3e..36b249ab73d0 100644
--- a/tools/lkl/Makefile.autoconf
+++ b/tools/lkl/Makefile.autoconf
@@ -14,7 +14,7 @@ define find_include
 endef

 define is_defined
-$(shell $(CC) -dM -E - </dev/null | grep $(1))
+$(shell $(CC) -D__FIBER__ -dM -E - </dev/null | grep $(1))
 endef

 define android_host
@@ -28,6 +28,7 @@ endef
 define fiber_host
   $(call set_autoconf_var,FIBER,y)
   LDFLAGS += -lrt
+  CFLAGS += -D__FIBER__
 endef

 define virtio_net_dpdk
diff --git a/tools/lkl/include/lk/kernel/thread.h b/tools/lkl/include/lk/kernel/thread.h
index 9fcef3eb2c6c..52692057e672 100644
--- a/tools/lkl/include/lk/kernel/thread.h
+++ b/tools/lkl/include/lk/kernel/thread.h
@@ -68,7 +68,7 @@ enum thread_tls_list {
 #ifdef WITH_LIB_LKUSER
     TLS_ENTRY_LKUSER,
 #endif
-    MAX_TLS_ENTRY
+    MAX_TLS_ENTRY = 4
 };

 #define THREAD_FLAG_DETACHED                  (1<<0)
diff --git a/tools/lkl/lib/posix-host.c b/tools/lkl/lib/posix-host.c
index 6731133eb46c..d3bc6a832993 100644
--- a/tools/lkl/lib/posix-host.c
+++ b/tools/lkl/lib/posix-host.c
@@ -302,6 +302,7 @@ void lkl_thread_init(void)
 {
         thread_init_early();
         thread_init();
+        timer_init();
         thread_create_idle();
         thread_set_priority(DEFAULT_PRIORITY);