diff --git a/library/x509_crl.c b/library/x509_crl.c
index e193919..5c2c7d5 100644
--- a/library/x509_crl.c
+++ b/library/x509_crl.c
@@ -53,7 +53,7 @@
 #include <stdlib.h>
 #include <stdio.h>
 #define mbedtls_free       free
-#define mbedtls_malloc     malloc
+#define mbedtls_calloc    calloc
 #define mbedtls_snprintf   snprintf
 #endif
 
@@ -238,7 +238,7 @@
 
         if( *p < end )
         {
-            cur_entry->next = mbedtls_malloc( sizeof( mbedtls_x509_crl_entry ) );
+            cur_entry->next = mbedtls_calloc( 1, sizeof( mbedtls_x509_crl_entry ) );
 
             if( cur_entry->next == NULL )
                 return( MBEDTLS_ERR_X509_MALLOC_FAILED );
@@ -281,7 +281,7 @@
 
     if( crl->version != 0 && crl->next == NULL )
     {
-        crl->next = mbedtls_malloc( sizeof( mbedtls_x509_crl ) );
+        crl->next = mbedtls_calloc( 1, sizeof( mbedtls_x509_crl ) );
 
         if( crl->next == NULL )
         {
@@ -296,7 +296,7 @@
     /*
      * Copy raw DER-encoded CRL
      */
-    if( ( p = mbedtls_malloc( buflen ) ) == NULL )
+    if( ( p = mbedtls_calloc( 1, buflen ) ) == NULL )
         return( MBEDTLS_ERR_X509_MALLOC_FAILED );
 
     memcpy( p, buf, buflen );