diff --git a/run.c b/run.c
index 624a784..4069f59 100644
--- a/run.c
+++ b/run.c
@@ -898,7 +898,7 @@ int format(char **pbuf, int *pbufsize, const char *s, Node *a)	/* printf-like co
 			break;
 		case 'o': case 'x': case 'X': case 'u':
 			flag = *(s-1) == 'l' ? 'd' : 'u';
-			*(t-1) = 'l';
+			*(t-1) = 'j';
 			*t = *s;
 			*++t = '\0';
 			break;
@@ -934,8 +934,8 @@ int format(char **pbuf, int *pbufsize, const char *s, Node *a)	/* printf-like co
 		case 'a':
 		case 'A':
 		case 'f':	snprintf(p, BUFSZ(p), fmt, getfval(x)); break;
-		case 'd':	snprintf(p, BUFSZ(p), fmt, (long) getfval(x)); break;
-		case 'u':	snprintf(p, BUFSZ(p), fmt, (int) getfval(x)); break;
+		case 'd':	snprintf(p, BUFSZ(p), fmt, (intmax_t) getfval(x)); break;
+		case 'u':	snprintf(p, BUFSZ(p), fmt, (uintmax_t) getfval(x)); break;
 		case 's':
 			t = getsval(x);
 			n = strlen(t);