diff --git a/tests/suites/helpers.function b/tests/suites/helpers.function
index 6977cfa..b9f01ad 100644
--- a/tests/suites/helpers.function
+++ b/tests/suites/helpers.function
@@ -4,7 +4,7 @@
 #include <stdio.h>
 #define mbedtls_printf     printf
 #define mbedtls_fprintf    fprintf
-#define mbedtls_malloc     malloc
+#define mbedtls_calloc    calloc
 #define mbedtls_free       free
 #define mbedtls_exit       exit
 #define mbedtls_fprintf    fprintf
@@ -123,7 +123,7 @@
     void *p;
     size_t actual_len = ( len != 0 ) ? len : 1;
 
-    p = mbedtls_malloc( actual_len );
+    p = mbedtls_calloc( 1, actual_len );
     assert( p != NULL );
 
     memset( p, 0x00, actual_len );
@@ -150,7 +150,7 @@
     if( *olen == 0 )
         return( zero_alloc( *olen ) );
 
-    obuf = mbedtls_malloc( *olen );
+    obuf = mbedtls_calloc( 1, *olen );
     assert( obuf != NULL );
 
     (void) unhexify( obuf, ibuf );