diff --git a/git-compat-util.h b/git-compat-util.h
index db2836fbdee6c1e069e6f5955031087d778cddf5..2ac832f3b4ad1566c7e744505205c13f7b05347f 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -154,10 +154,7 @@ extern void die(const char *err, ...) NORETURN __attribute__((format (printf, 1,
 extern int error(const char *err, ...) __attribute__((format (printf, 1, 2)));
 extern void warning(const char *err, ...) __attribute__((format (printf, 1, 2)));
 
-extern void set_usage_routine(void (*routine)(const char *err) NORETURN);
 extern void set_die_routine(void (*routine)(const char *err, va_list params) NORETURN);
-extern void set_error_routine(void (*routine)(const char *err, va_list params));
-extern void set_warn_routine(void (*routine)(const char *warn, va_list params));
 
 extern int prefixcmp(const char *str, const char *prefix);
 extern time_t tm_to_time_t(const struct tm *tm);
diff --git a/usage.c b/usage.c
index a5fc4ec5fae66823266862fa0254474696c220e6..24f5fc00c2501c1a1cc317f0b74b458ea50c8b0e 100644
--- a/usage.c
+++ b/usage.c
@@ -41,27 +41,11 @@ static void (*die_routine)(const char *err, va_list params) NORETURN = die_built
 static void (*error_routine)(const char *err, va_list params) = error_builtin;
 static void (*warn_routine)(const char *err, va_list params) = warn_builtin;
 
-void set_usage_routine(void (*routine)(const char *err) NORETURN)
-{
-	usage_routine = routine;
-}
-
 void set_die_routine(void (*routine)(const char *err, va_list params) NORETURN)
 {
 	die_routine = routine;
 }
 
-void set_error_routine(void (*routine)(const char *err, va_list params))
-{
-	error_routine = routine;
-}
-
-void set_warn_routine(void (*routine)(const char *warn, va_list params))
-{
-	warn_routine = routine;
-}
-
-
 void usage(const char *err)
 {
 	usage_routine(err);