diff --git a/library/entropy.c b/library/entropy.c
index b45384d..d3c1327 100644
--- a/library/entropy.c
+++ b/library/entropy.c
@@ -68,8 +68,10 @@
 #endif
 
 #if defined(MBEDTLS_ENTROPY_SHA512_ACCUMULATOR)
+    mbedtls_sha512_init( &ctx->accumulator );
     mbedtls_sha512_starts( &ctx->accumulator, 0 );
 #else
+    mbedtls_sha256_init( &ctx->accumulator );
     mbedtls_sha256_starts( &ctx->accumulator, 0 );
 #endif
 #if defined(MBEDTLS_HAVEGE_C)
@@ -105,6 +107,13 @@
 #if defined(MBEDTLS_HAVEGE_C)
     mbedtls_havege_free( &ctx->havege_data );
 #endif
+
+#if defined(MBEDTLS_ENTROPY_SHA512_ACCUMULATOR)
+    mbedtls_sha512_free( &ctx->accumulator );
+#else
+    mbedtls_sha256_free( &ctx->accumulator );
+#endif
+
 #if defined(MBEDTLS_THREADING_C)
     mbedtls_mutex_free( &ctx->mutex );
 #endif