diff --git a/library/pkwrite.c b/library/pkwrite.c
index c2c5623..49a21bf 100644
--- a/library/pkwrite.c
+++ b/library/pkwrite.c
@@ -31,6 +31,7 @@
 #include "mbedtls/asn1write.h"
 #include "mbedtls/oid.h"
 #include "mbedtls/platform_util.h"
+#include "mbedtls/error.h"
 
 #include <string.h>
 
@@ -77,7 +78,7 @@
 static int pk_write_rsa_pubkey( unsigned char **p, unsigned char *start,
                                 mbedtls_rsa_context *rsa )
 {
-    int ret;
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     size_t len = 0;
     mbedtls_mpi T;
 
@@ -116,7 +117,7 @@
 static int pk_write_ec_pubkey( unsigned char **p, unsigned char *start,
                                mbedtls_ecp_keypair *ec )
 {
-    int ret;
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     size_t len = 0;
     unsigned char buf[MBEDTLS_ECP_MAX_PT_LEN];
 
@@ -144,7 +145,7 @@
 static int pk_write_ec_param( unsigned char **p, unsigned char *start,
                               mbedtls_ecp_keypair *ec )
 {
-    int ret;
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     size_t len = 0;
     const char *oid;
     size_t oid_len;
@@ -163,7 +164,7 @@
 static int pk_write_ec_private( unsigned char **p, unsigned char *start,
                                 mbedtls_ecp_keypair *ec )
 {
-    int ret;
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     size_t byte_length = ( ec->grp.pbits + 7 ) / 8;
     unsigned char tmp[MBEDTLS_ECP_MAX_BYTES];
 
@@ -181,7 +182,7 @@
 int mbedtls_pk_write_pubkey( unsigned char **p, unsigned char *start,
                              const mbedtls_pk_context *key )
 {
-    int ret;
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     size_t len = 0;
 
     PK_VALIDATE_RET( p != NULL );
@@ -229,7 +230,7 @@
 
 int mbedtls_pk_write_pubkey_der( mbedtls_pk_context *key, unsigned char *buf, size_t size )
 {
-    int ret;
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     unsigned char *c;
     size_t len = 0, par_len = 0, oid_len;
     mbedtls_pk_type_t pk_type;
@@ -315,7 +316,7 @@
 
 int mbedtls_pk_write_key_der( mbedtls_pk_context *key, unsigned char *buf, size_t size )
 {
-    int ret;
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     unsigned char *c;
     size_t len = 0;
 
@@ -558,7 +559,7 @@
 
 int mbedtls_pk_write_pubkey_pem( mbedtls_pk_context *key, unsigned char *buf, size_t size )
 {
-    int ret;
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     unsigned char output_buf[PUB_DER_MAX_BYTES];
     size_t olen = 0;
 
@@ -583,7 +584,7 @@
 
 int mbedtls_pk_write_key_pem( mbedtls_pk_context *key, unsigned char *buf, size_t size )
 {
-    int ret;
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     unsigned char output_buf[PRV_DER_MAX_BYTES];
     const char *begin, *end;
     size_t olen = 0;