diff --git a/crypto/drbg.c b/crypto/drbg.c
index a7c2314..ab6ef1d 100644
--- a/crypto/drbg.c
+++ b/crypto/drbg.c
@@ -626,7 +626,7 @@
 	return len;
 }
 
-static struct drbg_state_ops drbg_ctr_ops = {
+static const struct drbg_state_ops drbg_ctr_ops = {
 	.update		= drbg_ctr_update,
 	.generate	= drbg_ctr_generate,
 	.crypto_init	= drbg_init_sym_kernel,
@@ -752,7 +752,7 @@
 	return len;
 }
 
-static struct drbg_state_ops drbg_hmac_ops = {
+static const struct drbg_state_ops drbg_hmac_ops = {
 	.update		= drbg_hmac_update,
 	.generate	= drbg_hmac_generate,
 	.crypto_init	= drbg_init_hash_kernel,
@@ -1032,7 +1032,7 @@
  * scratchpad usage: as update and generate are used isolated, both
  * can use the scratchpad
  */
-static struct drbg_state_ops drbg_hash_ops = {
+static const struct drbg_state_ops drbg_hash_ops = {
 	.update		= drbg_hash_update,
 	.generate	= drbg_hash_generate,
 	.crypto_init	= drbg_init_hash_kernel,