diff --git a/src/flisp/Makefile b/src/flisp/Makefile
index 67d35ffe9ae09..5d7cf6fc51ccd 100644
--- a/src/flisp/Makefile
+++ b/src/flisp/Makefile
@@ -28,7 +28,7 @@ LIBS += -lpthread
 endif
 
 FLAGS := -I$(LLTDIR) $(CFLAGS) $(HFILEDIRS:%=-I%) \
-        -I$(LIBUV_INC) -I$(build_includedir) $(LIBDIRS:%=-L%) \
+        -I$(LIBUV_INC) -I$(UTF8PROC_INC) -I$(build_includedir) $(LIBDIRS:%=-L%) \
         -DLIBRARY_EXPORTS -DUTF8PROC_EXPORTS
 ifneq ($(USEMSVC), 1)
 FLAGS += -Wall -Wno-strict-aliasing -DUSE_COMPUTED_GOTO -fvisibility=hidden -Wpointer-arith -Wundef