diff --git a/include/mbedtls/entropy.h b/include/mbedtls/entropy.h
index d707bdd..78591e7 100644
--- a/include/mbedtls/entropy.h
+++ b/include/mbedtls/entropy.h
@@ -124,7 +124,7 @@
 #if defined(MBEDTLS_ENTROPY_SHA512_ACCUMULATOR)
     mbedtls_sha512_context  MBEDTLS_PRIVATE(accumulator);
 #else
-    mbedtls_sha256_context  accumulator;
+    mbedtls_sha256_context  MBEDTLS_PRIVATE(accumulator);
 #endif
     int             MBEDTLS_PRIVATE(source_count); /* Number of entries used in source. */
     mbedtls_entropy_source_state    MBEDTLS_PRIVATE(source)[MBEDTLS_ENTROPY_MAX_SOURCES];