diff --git a/src/misc/fp_ident.c b/src/misc/fp_ident.c
index da5c793..e0a7907 100644
--- a/src/misc/fp_ident.c
+++ b/src/misc/fp_ident.c
@@ -70,7 +70,7 @@ const char *fp_ident(void)
 #ifdef TFM_HUGE
 " TFM_HUGE "
 #endif
-"\n", __DATE__, sizeof(fp_digit), sizeof(fp_word), FP_MAX_SIZE);
+"\n", __DATE__, (unsigned long)sizeof(fp_digit), (unsigned long)sizeof(fp_word), FP_MAX_SIZE);
 
    if (sizeof(fp_digit) == sizeof(fp_word)) {
       strncat(buf, "WARNING: sizeof(fp_digit) == sizeof(fp_word), this build is likely to not work properly.\n",