diff --git a/Makefile b/Makefile
index 1386819..d2ceff2 100644
--- a/Makefile
+++ b/Makefile
@@ -10,13 +10,28 @@ INSTALL_DATA = $(INSTALL) -m 644
 
 prefix = /usr/local
 
+# ifdef check allows the user to pass custom dirs
+# as per the README
+
 # The directory to install todo.sh in.
-bindir = $(prefix)/bin
+ifdef INSTALL_DIR
+	bindir = $(INSTALL_DIR)
+else
+	bindir = $(prefix)/bin
+endif
 
 # The directory to install the config file in.
-sysconfdir = $(prefix)/etc
+ifdef CONFIG_DIR
+	sysconfdir = $(CONFIG_DIR)
+else
+	sysconfdir = $(prefix)/etc
+endif
 
-datarootdir = $(prefix)/share
+ifdef BASH_COMPLETION
+	datarootdir = $(BASH_COMPLETION)
+else
+	datarootdir = $(prefix)/share
+endif
 
 # Dynamically detect/generate version file as necessary
 # This file will define a variable called VERSION.
@@ -85,4 +100,4 @@ test: aggregate-results
 	rm -rf tests/test-results
     
 # Force tests to get run every time
-.PHONY: test test-pre-clean aggregate-results $(TESTS)
+.PHONY: test test-pre-clean aggregate-results $(TESTS)
\ No newline at end of file
diff --git a/README.md b/README.md
index b077149..bda1a28 100644
--- a/README.md
+++ b/README.md
@@ -42,7 +42,7 @@ make test
 - `BASH_COMPLETION`: PATH for autocompletion scripts (default to /etc/bash_completion.d)
 
 ```shell
-make install CONFIG_DIR=/etc INSTALL_DIR=/usr/bin BASH_COMPLETION_DIR=/usr/share/bash-completion/completions
+make install CONFIG_DIR=/etc INSTALL_DIR=/usr/bin BASH_COMPLETION=/usr/share/bash-completion/completions
 ```
 
 #### Arch Linux (AUR)