diff --git a/scripts/dtc/data.c b/scripts/dtc/data.c
index dd2e3d3..fe555e8 100644
--- a/scripts/dtc/data.c
+++ b/scripts/dtc/data.c
@@ -217,7 +217,7 @@
 	return d;
 }
 
-struct data data_append_markers(struct data d, struct marker *m)
+static struct data data_append_markers(struct data d, struct marker *m)
 {
 	struct marker **mp = &d.markers;
 
diff --git a/scripts/dtc/libfdt/fdt_ro.c b/scripts/dtc/libfdt/fdt_ro.c
index fbbba44..22e69291 100644
--- a/scripts/dtc/libfdt/fdt_ro.c
+++ b/scripts/dtc/libfdt/fdt_ro.c
@@ -411,7 +411,7 @@
 					     &phandle, sizeof(phandle));
 }
 
-int _stringlist_contains(const char *strlist, int listlen, const char *str)
+static int _stringlist_contains(const char *strlist, int listlen, const char *str)
 {
 	int len = strlen(str);
 	const char *p;
diff --git a/scripts/dtc/treesource.c b/scripts/dtc/treesource.c
index ebeb6eb..1521ff1 100644
--- a/scripts/dtc/treesource.c
+++ b/scripts/dtc/treesource.c
@@ -52,7 +52,7 @@
 		fputc('\t', f);
 }
 
-int isstring(char c)
+static int isstring(char c)
 {
 	return (isprint(c)
 		|| (c == '\0')