diff --git a/components/bootloader_support/src/idf/secure_boot_signatures.c b/components/bootloader_support/src/idf/secure_boot_signatures.c
index aae4599b7..d2021cf1a 100644
--- a/components/bootloader_support/src/idf/secure_boot_signatures.c
+++ b/components/bootloader_support/src/idf/secure_boot_signatures.c
@@ -207,6 +207,7 @@ esp_err_t esp_secure_boot_verify_rsa_signature_block(const ets_secure_boot_signa
     }
 
     mbedtls_entropy_init(&entropy);
+    mbedtls_ctr_drbg_init(&ctr_drbg);
     ret = mbedtls_ctr_drbg_seed(&ctr_drbg, mbedtls_entropy_func, &entropy, NULL, 0);
     if (ret != 0) {
         ESP_LOGE(TAG, "mbedtls_ctr_drbg_seed returned -0x%04x\n", ret);