diff --git a/library/hmac_drbg.c b/library/hmac_drbg.c
index f71c95c..f811885 100644
--- a/library/hmac_drbg.c
+++ b/library/hmac_drbg.c
@@ -35,6 +35,7 @@
 
 #include "mbedtls/hmac_drbg.h"
 #include "mbedtls/platform_util.h"
+#include "mbedtls/error.h"
 
 #include <string.h>
 
@@ -127,7 +128,7 @@
                         const mbedtls_md_info_t * md_info,
                         const unsigned char *data, size_t data_len )
 {
-    int ret;
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
 
     if( ( ret = mbedtls_md_setup( &ctx->md_ctx, md_info, 1 ) ) != 0 )
         return( ret );
@@ -159,7 +160,7 @@
 {
     unsigned char seed[MBEDTLS_HMAC_DRBG_MAX_SEED_INPUT];
     size_t seedlen = 0;
-    int ret;
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
 
     {
         size_t total_entropy_len;
@@ -251,7 +252,7 @@
                     const unsigned char *custom,
                     size_t len )
 {
-    int ret;
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     size_t md_size;
 
     if( ( ret = mbedtls_md_setup( &ctx->md_ctx, md_info, 1 ) ) != 0 )
@@ -329,7 +330,7 @@
                                unsigned char *output, size_t out_len,
                                const unsigned char *additional, size_t add_len )
 {
-    int ret;
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     mbedtls_hmac_drbg_context *ctx = (mbedtls_hmac_drbg_context *) p_rng;
     size_t md_len = mbedtls_md_get_size( ctx->md_ctx.md_info );
     size_t left = out_len;
@@ -398,7 +399,7 @@
  */
 int mbedtls_hmac_drbg_random( void *p_rng, unsigned char *output, size_t out_len )
 {
-    int ret;
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     mbedtls_hmac_drbg_context *ctx = (mbedtls_hmac_drbg_context *) p_rng;
 
 #if defined(MBEDTLS_THREADING_C)
@@ -434,7 +435,7 @@
 #if defined(MBEDTLS_FS_IO)
 int mbedtls_hmac_drbg_write_seed_file( mbedtls_hmac_drbg_context *ctx, const char *path )
 {
-    int ret;
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     FILE *f;
     unsigned char buf[ MBEDTLS_HMAC_DRBG_MAX_INPUT ];