3 files changed, 3 insertions, 3 deletions
diff --git a/ext/psych/psych.c b/ext/psych/psych.c
index 69ff1d8dfc..3bb59bfc11 100644
--- a/ext/psych/psych.c
+++ b/ext/psych/psych.c
@@ -20,7 +20,7 @@ static VALUE libyaml_version(VALUE module)
 
 VALUE mPsych;
 
-void Init_psych()
+void Init_psych(void)
 {
     mPsych = rb_define_module("Psych");
 
diff --git a/ext/psych/psych_emitter.c b/ext/psych/psych_emitter.c
index f0d032649c..d833b59c06 100644
--- a/ext/psych/psych_emitter.c
+++ b/ext/psych/psych_emitter.c
@@ -504,7 +504,7 @@ static VALUE set_line_width(VALUE self, VALUE width)
     return width;
 }
 
-void Init_psych_emitter()
+void Init_psych_emitter(void)
 {
     VALUE psych     = rb_define_module("Psych");
     VALUE handler   = rb_define_class_under(psych, "Handler", rb_cObject);
diff --git a/ext/psych/psych_parser.c b/ext/psych/psych_parser.c
index 8c65ce1307..19c7484124 100644
--- a/ext/psych/psych_parser.c
+++ b/ext/psych/psych_parser.c
@@ -535,7 +535,7 @@ static VALUE mark(VALUE self)
     return rb_class_new_instance(3, args, mark_klass);
 }
 
-void Init_psych_parser()
+void Init_psych_parser(void)
 {
 #if 0
     mPsych = rb_define_module("Psych");