diff --git a/scripts/kconfig/symbol.c b/scripts/kconfig/symbol.c
index 18f3e5c..6c8fbbb 100644
--- a/scripts/kconfig/symbol.c
+++ b/scripts/kconfig/symbol.c
@@ -36,7 +36,7 @@
 
 struct expr *sym_env_list;
 
-void sym_add_default(struct symbol *sym, const char *def)
+static void sym_add_default(struct symbol *sym, const char *def)
 {
 	struct property *prop = prop_alloc(P_DEFAULT, sym);
 
@@ -125,7 +125,7 @@
 	return NULL;
 }
 
-struct property *sym_get_range_prop(struct symbol *sym)
+static struct property *sym_get_range_prop(struct symbol *sym)
 {
 	struct property *prop;
 
@@ -943,7 +943,7 @@
 	return "unknown";
 }
 
-void prop_add_env(const char *env)
+static void prop_add_env(const char *env)
 {
 	struct symbol *sym, *sym2;
 	struct property *prop;