diff --git a/examples/example_null/Makefile b/examples/example_null/Makefile
index 9cd0d0635..91c8dd78c 100644
--- a/examples/example_null/Makefile
+++ b/examples/example_null/Makefile
@@ -14,6 +14,7 @@ EXE = example_null
 IMGUI_DIR = ../..
 SOURCES = main.cpp
 SOURCES += $(IMGUI_DIR)/imgui.cpp $(IMGUI_DIR)/imgui_demo.cpp $(IMGUI_DIR)/imgui_draw.cpp $(IMGUI_DIR)/imgui_tables.cpp $(IMGUI_DIR)/imgui_widgets.cpp
+SOURCES += $(IMGUI_DIR)/backends/imgui_impl_null.cpp
 OBJS = $(addsuffix .o, $(basename $(notdir $(SOURCES))))
 UNAME_S := $(shell uname -s)