diff --git a/makefile b/makefile
index 58a9e74..64615b6 100644
--- a/makefile
+++ b/makefile
@@ -32,8 +32,6 @@ os :=
 ifeq ($(uname), Linux)
  os := $(shell head -n 1 /etc/issue | cut -d" " -f1)
  ifeq ($(os), Ubuntu)
-    EXTEN = exten
-    EXTENZ = exten2
     LIBSG = -L/usr/X11R6/lib -lGLU -lGL -lX11 -lm
  endif
  ifeq ($(os), Debian)
@@ -278,7 +276,7 @@ LIBSOGL = -lglut -lGLU -lGL -lXmu -lX11 -lm
 #
 #LIBSG = -L/usr/X11R6/lib -Wl,-framework -Wl,GLUT -Wl,-framework -Wl,OpenGL -Wl,-framework -Wl,Cocoa -lGLU -lGL -lXmu -lX11 -lm
 
-all:	molden gmolden ambfor/ambfor ambfor/ambmd surf/surf $(EXTEN)
+all:	molden gmolden ambfor/ambfor ambfor/ambmd surf/surf
 xwin.o:	xwin.c rots.h
 xwingl.o:	xwin.c rots.h
 
@@ -344,5 +342,5 @@ exten:
 exten2:
 	./register_extension.sh /usr/local/bin
 
-install:	$(EXTENZ)
+install:
 	sudo install -t /usr/local/bin -m 755 molden gmolden ambfor/ambfor ambfor/ambmd surf/surf