diff --git a/Makefile.linux b/Makefile.linux
index 551c909..b39e398 100644
--- a/Makefile.linux
+++ b/Makefile.linux
@@ -3,7 +3,7 @@ CXXFLAGS        += $(INCFLAGS) -g -Wall --std=c++11 -O2
 LDFLAGS         += -L/opt/local/lib
 LDLIBS          += -lglfw -lao -lGL -lGLEW
 
-OBJECTS         = apple2e.o dis6502.o fake6502.o interface.o
+OBJECTS         = apple2e.o dis6502.o fake6502.o interface.o gl_utility.o
 
 # keyboard.o