diff --git a/src/internal/perk_driver_impl.h b/src/internal/perk_driver_impl.h
index 7e9e4f7..757dec0 100644
--- a/src/internal/perk_driver_impl.h
+++ b/src/internal/perk_driver_impl.h
@@ -9,6 +9,7 @@
 #include <perk/perk_meta.h>
 #include "argv/argv.h"
 
+extern int perk_main(int, char **, char **);
 extern const struct argv_option pe_default_options[];
 
 enum app_tags {
diff --git a/src/perk.c b/src/perk.c
index 22d42a9..352d675 100644
--- a/src/perk.c
+++ b/src/perk.c
@@ -9,6 +9,7 @@
 #include <perk/perk.h>
 #include <perk/perk_output.h>
 #include "perk_version.h"
+#include "perk_driver_impl.h"
 
 #ifndef PERK_DRIVER_FLAGS
 #define PERK_DRIVER_FLAGS	PERK_DRIVER_VERBOSITY_ERRORS \