diff --git a/library/chachapoly.c b/library/chachapoly.c
index dc643dd..f0af5de 100644
--- a/library/chachapoly.c
+++ b/library/chachapoly.c
@@ -30,6 +30,7 @@
 
 #include "mbedtls/chachapoly.h"
 #include "mbedtls/platform_util.h"
+#include "mbedtls/error.h"
 
 #include <string.h>
 
@@ -122,7 +123,7 @@
 int mbedtls_chachapoly_setkey( mbedtls_chachapoly_context *ctx,
                                const unsigned char key[32] )
 {
-    int ret;
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     CHACHAPOLY_VALIDATE_RET( ctx != NULL );
     CHACHAPOLY_VALIDATE_RET( key != NULL );
 
@@ -135,7 +136,7 @@
                                const unsigned char nonce[12],
                                mbedtls_chachapoly_mode_t mode  )
 {
-    int ret;
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     unsigned char poly1305_key[64];
     CHACHAPOLY_VALIDATE_RET( ctx != NULL );
     CHACHAPOLY_VALIDATE_RET( nonce != NULL );
@@ -191,7 +192,7 @@
                                const unsigned char *input,
                                unsigned char *output )
 {
-    int ret;
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     CHACHAPOLY_VALIDATE_RET( ctx != NULL );
     CHACHAPOLY_VALIDATE_RET( len == 0 || input != NULL );
     CHACHAPOLY_VALIDATE_RET( len == 0 || output != NULL );
@@ -240,7 +241,7 @@
 int mbedtls_chachapoly_finish( mbedtls_chachapoly_context *ctx,
                                unsigned char mac[16] )
 {
-    int ret;
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     unsigned char len_block[16];
     CHACHAPOLY_VALIDATE_RET( ctx != NULL );
     CHACHAPOLY_VALIDATE_RET( mac != NULL );
@@ -304,7 +305,7 @@
                                      unsigned char *output,
                                      unsigned char tag[16] )
 {
-    int ret;
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
 
     ret = mbedtls_chachapoly_starts( ctx, nonce, mode );
     if( ret != 0 )
@@ -354,7 +355,7 @@
                                      const unsigned char *input,
                                      unsigned char *output )
 {
-    int ret;
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     unsigned char check_tag[16];
     size_t i;
     int diff;
@@ -492,7 +493,7 @@
 {
     mbedtls_chachapoly_context ctx;
     unsigned i;
-    int ret;
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     unsigned char output[200];
     unsigned char mac[16];