2 files changed, 2 insertions, 2 deletions
diff --git a/pc-bios/s390-ccw/libc.c b/pc-bios/s390-ccw/libc.c
index 38ea77d7aa..a786566c4c 100644
--- a/pc-bios/s390-ccw/libc.c
+++ b/pc-bios/s390-ccw/libc.c
@@ -63,7 +63,7 @@ uint64_t atoui(const char *str)
  */
 char *uitoa(uint64_t num, char *str, size_t len)
 {
-    size_t num_idx = 1; /* account for NUL */
+    long num_idx = 1; /* account for NUL */
     uint64_t tmp = num;
 
     IPL_assert(str != NULL, "uitoa: no space allocated to store string");
diff --git a/pc-bios/s390-ccw/libc.h b/pc-bios/s390-ccw/libc.h
index 63ece70c6b..818517ff5d 100644
--- a/pc-bios/s390-ccw/libc.h
+++ b/pc-bios/s390-ccw/libc.h
@@ -12,7 +12,7 @@
 #ifndef S390_CCW_LIBC_H
 #define S390_CCW_LIBC_H
 
-typedef long               size_t;
+typedef unsigned long      size_t;
 typedef int                bool;
 typedef unsigned char      uint8_t;
 typedef unsigned short     uint16_t;