--- a/Makefile.orig	2019-04-11 11:37:20.000000000 -0700
+++ b/Makefile	2019-04-11 11:37:53.000000000 -0700
@@ -71,7 +71,7 @@
 # Leave INSTALL_ROOT empty (or just don't execute "make install") to
 # not install gsm and toast outside of this directory.
 
-INSTALL_ROOT	=
+INSTALL_ROOT	?=
 
 # Where do you want to install the gsm library, header file, and manpages?
 #
@@ -80,8 +80,8 @@
 
 GSM_INSTALL_ROOT = $(INSTALL_ROOT)
 GSM_INSTALL_LIB = $(GSM_INSTALL_ROOT)/lib
-GSM_INSTALL_INC = $(GSM_INSTALL_ROOT)/inc
-GSM_INSTALL_MAN = $(GSM_INSTALL_ROOT)/man/man3
+GSM_INSTALL_INC = $(GSM_INSTALL_ROOT)/include
+GSM_INSTALL_MAN = $(GSM_INSTALL_ROOT)/share/man/man3
 
 
 # Where do you want to install the toast binaries and their manpage?
@@ -91,7 +91,7 @@
 
 TOAST_INSTALL_ROOT	  = $(INSTALL_ROOT)
 TOAST_INSTALL_BIN = $(TOAST_INSTALL_ROOT)/bin
-TOAST_INSTALL_MAN = $(TOAST_INSTALL_ROOT)/man/man1
+TOAST_INSTALL_MAN = $(TOAST_INSTALL_ROOT)/share/man/man1
 
 #  Other tools