diff --git a/.gitignore b/.gitignore
index 06ab994..17fe96d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,4 @@
 src/secretkey.h
 src/secretkey.bin
-src/keygen
+src/genkey
+src/exim-kitencrypt-dlfunc.so
diff --git a/src/Makefile b/src/Makefile
new file mode 100644
index 0000000..dd2c27d
--- /dev/null
+++ b/src/Makefile
@@ -0,0 +1,10 @@
+exim-kitencrypt-dlfunc.so: exim-kitencrypt-dlfunc.c exim-kitencrypt-dlfunc.h secretkey.h
+	gcc exim-kitencrypt-dlfunc.c -fPIC -fpic -shared -I/usr/include/exim4 -export-dynamic -o exim-kitencrypt-dlfunc.so
+
+genkey: genkey.c
+	gcc -lsodium -o genkey genkey.c
+
+secretkey.h: secretkey.bin
+
+secretkey.bin: genkey
+	./genkey
diff --git a/src/exim4encrypt.c b/src/exim-kitencrypt-dlfunc.c
similarity index 97%
rename from src/exim4encrypt.c
rename to src/exim-kitencrypt-dlfunc.c
index 9f910f5..1c39102 100644
--- a/src/exim4encrypt.c
+++ b/src/exim-kitencrypt-dlfunc.c
@@ -1,7 +1,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <strings.h>
-#include "exim4encrypt.h"
+#include "exim-kitencrypt-dlfunc.h"
 #include "secretkey.h"
 
 int kitencrypt(uschar **yield, int argc, uschar *argv[]) {
diff --git a/src/exim4encrypt.h b/src/exim-kitencrypt-dlfunc.h
similarity index 100%
rename from src/exim4encrypt.h
rename to src/exim-kitencrypt-dlfunc.h