diff --git a/src/prng.c b/src/prng.c
index acc6cf7f..f350d3fb 100644
--- a/src/prng.c
+++ b/src/prng.c
@@ -377,7 +377,7 @@ int nwipe_aes_ctr_prng_init( NWIPE_PRNG_INIT_SIGNATURE )
 
     // Initialize the PRNG state with the provided seed.
     if( aes_ctr_prng_init(
-            (aes_ctr_state_t*) *state, (unsigned long*) ( seed->s ), seed->length / sizeof( unsigned long ) )
+            (aes_ctr_state_t*) *state, (uint64_t*) ( seed->s ), seed->length / sizeof( uint64_t ) )
         != 0 )
     {
         nwipe_log( NWIPE_LOG_SANITY, "Fatal error occured during PRNG init in OpenSSL." );