diff --git a/busybox.h b/busybox.h
index fc5e8d874..2fc0cc7e0 100644
--- a/busybox.h
+++ b/busybox.h
@@ -167,7 +167,8 @@ struct suffix_mult {
 	int mult;
 };
 
-extern unsigned long parse_number(const char *numstr, struct suffix_mult *suffixes);
+extern unsigned long parse_number(const char *numstr,
+		const struct suffix_mult *suffixes);
 
 
 /* These parse entries in /etc/passwd and /etc/group.  This is desirable
diff --git a/coreutils/dd.c b/coreutils/dd.c
index 582310681..75bbfbac2 100644
--- a/coreutils/dd.c
+++ b/coreutils/dd.c
@@ -30,7 +30,7 @@
 #include <string.h>
 #include <fcntl.h>
 
-static struct suffix_mult dd_suffixes[] = {
+static const struct suffix_mult dd_suffixes[] = {
 	{ "c", 1 },
 	{ "w", 2 },
 	{ "b", 512 },
diff --git a/coreutils/tail.c b/coreutils/tail.c
index 40511aa7b..d45b29c4c 100644
--- a/coreutils/tail.c
+++ b/coreutils/tail.c
@@ -30,7 +30,7 @@
 #include <unistd.h>
 #include <sys/types.h>
 
-static struct suffix_mult tail_suffixes[] = {
+static const struct suffix_mult tail_suffixes[] = {
 	{ "b", 512 },
 	{ "k", 1024 },
 	{ "m", 1048576 },
@@ -38,7 +38,7 @@ static struct suffix_mult tail_suffixes[] = {
 };
 
 #ifndef BB_FEATURE_SIMPLE_TAIL
-static struct suffix_mult null_suffixes[] = {
+static const struct suffix_mult null_suffixes[] = {
 	{ NULL, 0 }
 };
 #endif
diff --git a/dd.c b/dd.c
index 582310681..75bbfbac2 100644
--- a/dd.c
+++ b/dd.c
@@ -30,7 +30,7 @@
 #include <string.h>
 #include <fcntl.h>
 
-static struct suffix_mult dd_suffixes[] = {
+static const struct suffix_mult dd_suffixes[] = {
 	{ "c", 1 },
 	{ "w", 2 },
 	{ "b", 512 },
diff --git a/include/busybox.h b/include/busybox.h
index fc5e8d874..2fc0cc7e0 100644
--- a/include/busybox.h
+++ b/include/busybox.h
@@ -167,7 +167,8 @@ struct suffix_mult {
 	int mult;
 };
 
-extern unsigned long parse_number(const char *numstr, struct suffix_mult *suffixes);
+extern unsigned long parse_number(const char *numstr,
+		const struct suffix_mult *suffixes);
 
 
 /* These parse entries in /etc/passwd and /etc/group.  This is desirable
diff --git a/tail.c b/tail.c
index 40511aa7b..d45b29c4c 100644
--- a/tail.c
+++ b/tail.c
@@ -30,7 +30,7 @@
 #include <unistd.h>
 #include <sys/types.h>
 
-static struct suffix_mult tail_suffixes[] = {
+static const struct suffix_mult tail_suffixes[] = {
 	{ "b", 512 },
 	{ "k", 1024 },
 	{ "m", 1048576 },
@@ -38,7 +38,7 @@ static struct suffix_mult tail_suffixes[] = {
 };
 
 #ifndef BB_FEATURE_SIMPLE_TAIL
-static struct suffix_mult null_suffixes[] = {
+static const struct suffix_mult null_suffixes[] = {
 	{ NULL, 0 }
 };
 #endif
diff --git a/utility.c b/utility.c
index f99c613a1..aa1fa943b 100644
--- a/utility.c
+++ b/utility.c
@@ -1696,9 +1696,10 @@ struct BB_applet *find_applet_by_name(const char *name)
 }
 
 #if defined BB_DD || defined BB_TAIL
-unsigned long parse_number(const char *numstr, struct suffix_mult *suffixes)
+unsigned long parse_number(const char *numstr,
+		const struct suffix_mult *suffixes)
 {
-	struct suffix_mult *sm;
+	const struct suffix_mult *sm;
 	unsigned long int ret;
 	int len;
 	char *end;