diff --git a/subprojects/gst-devtools/validate/gst/validate/flow/gstvalidateflow.c b/subprojects/gst-devtools/validate/gst/validate/flow/gstvalidateflow.c
index c9aabdbbed..7b23955174 100644
--- a/subprojects/gst-devtools/validate/gst/validate/flow/gstvalidateflow.c
+++ b/subprojects/gst-devtools/validate/gst/validate/flow/gstvalidateflow.c
@@ -653,7 +653,7 @@ _execute_checkpoint (GstValidateScenario * scenario, GstValidateAction * action)
 }
 
 gboolean
-gst_validate_flow_init ()
+gst_validate_flow_init (void)
 {
   GList *tmp;
   gint default_generate = -1;
diff --git a/subprojects/gst-devtools/validate/gst/validate/gst-validate-extra-checks.c b/subprojects/gst-devtools/validate/gst/validate/gst-validate-extra-checks.c
index 270580bf7e..045be00b08 100644
--- a/subprojects/gst-devtools/validate/gst/validate/gst-validate-extra-checks.c
+++ b/subprojects/gst-devtools/validate/gst/validate/gst-validate-extra-checks.c
@@ -139,7 +139,7 @@ gst_validate_add_num_instances_check (GstStructure * structure)
 }
 
 gboolean
-gst_validate_extra_checks_init ()
+gst_validate_extra_checks_init (void)
 {
   GList *config, *tmp;
   config = gst_validate_get_config ("extrachecks");
diff --git a/subprojects/gst-devtools/validate/gst/validate/gst-validate-report.c b/subprojects/gst-devtools/validate/gst/validate/gst-validate-report.c
index 1d11cac2c2..e5a59eb233 100644
--- a/subprojects/gst-devtools/validate/gst/validate/gst-validate-report.c
+++ b/subprojects/gst-devtools/validate/gst/validate/gst-validate-report.c
@@ -1564,7 +1564,7 @@ gst_validate_abort (const gchar * format, ...)
 }
 
 gboolean
-is_tty ()
+is_tty (void)
 {
   return output_is_tty;
 }