diff --git a/workspace/TS100/Makefile b/workspace/TS100/Makefile
index 20c43f58..31aec7e0 100644
--- a/workspace/TS100/Makefile
+++ b/workspace/TS100/Makefile
@@ -95,7 +95,9 @@ LINKER_FLAGS=-Wl,--gc-sections 		\
 			-Wl,--wrap=free \
 			-o$(OUT_HEXFILE).elf 	\
 			-Wl,-Map=$(OUT_HEXFILE).map \
-			-lm -Wl,--undefined=vTaskSwitchContext \
+			-lm \
+			-Wl,--undefined=vTaskSwitchContext \
+			-Wl,--undefined=pxCurrentTCB \
 			-Wl,--defsym=__FLASH_SIZE__=$(flash_size) \
 			-Wl,--defsym=__BOOTLDR_SIZE__=$(bootldr_size) \
 			--specs=nano.specs