diff --git a/chip/g/dcrypto/aes.c b/chip/g/dcrypto/aes.c
index e42c43d58d..f5cc0e6d8f 100644
--- a/chip/g/dcrypto/aes.c
+++ b/chip/g/dcrypto/aes.c
@@ -16,6 +16,13 @@ static void set_control_register(
 	GWRITE_FIELD(KEYMGR, AES_CTRL, ENC_MODE, encrypt);
 	GWRITE_FIELD(KEYMGR, AES_CTRL, CTR_ENDIAN, CTRL_CTR_BIG_ENDIAN);
 	GWRITE_FIELD(KEYMGR, AES_CTRL, ENABLE, CTRL_ENABLE);
+
+	/* Turn off random nops (which are enabled by default). */
+	GWRITE_FIELD(KEYMGR, AES_RAND_STALL_CTL, STALL_EN, 0);
+	/* Configure random nop percentage at 25%. */
+	GWRITE_FIELD(KEYMGR, AES_RAND_STALL_CTL, FREQ, 1);
+	/* Now turn on random nops. */
+	GWRITE_FIELD(KEYMGR, AES_RAND_STALL_CTL, STALL_EN, 1);
 }
 
 static int wait_read_data(volatile uint32_t *addr)
diff --git a/chip/g/dcrypto/app_cipher.c b/chip/g/dcrypto/app_cipher.c
index 32c507cd65..a416720633 100644
--- a/chip/g/dcrypto/app_cipher.c
+++ b/chip/g/dcrypto/app_cipher.c
@@ -94,6 +94,12 @@ static int aes_init(struct APPKEY_CTX *ctx, enum dcrypto_appid appid,
 	GWRITE_FIELD(KEYMGR, AES_CTRL, ENC_MODE, ENCRYPT_MODE);
 	GWRITE_FIELD(KEYMGR, AES_CTRL, CTR_ENDIAN, CTRL_CTR_BIG_ENDIAN);
 
+	/*
+	 * For fixed-key, bulk ciphering, turn off random nops (which
+	 * are enabled by default).
+	 */
+	GWRITE_FIELD(KEYMGR, AES_RAND_STALL_CTL, STALL_EN, 0);
+
 	/* Enable hidden key usage, each appid gets its own
 	 * USR, with USR0 starting at 0x2a0.
 	 */