diff --git a/tools/Makefile b/tools/Makefile
index 81bcef39f..d9f64b8c0 100644
--- a/tools/Makefile
+++ b/tools/Makefile
@@ -7,7 +7,7 @@ PROGRAM += $(d)osx-bundle-restart-helper
 endif
 
 repack-thes-dict_OBJ  := $(d)repack-thes-dict.o $(TOP)lib/libaegisub.a
-repack-thes-dict_LIBS := $(LIBS_BOOST) $(LIBS_ICU)
+repack-thes-dict_LIBS := $(LIBS_BOOST) $(LIBS_ICU) $(LIBS_PTHREAD)
 repack-thes-dict_CPPFLAGS := -I$(TOP) -I$(TOP)libaegisub/include $(CFLAGS_ICU)
 
 PROGRAM += $(d)repack-thes-dict