diff --git a/py/mpprint.c b/py/mpprint.c
index 206cf2aa5cdc0b6de30492e4c4301ad1f54d26ad..cb49b1227a3b6c321392defe304105e8e4459669 100644
--- a/py/mpprint.c
+++ b/py/mpprint.c
@@ -494,16 +494,16 @@ int mp_vprintf(const mp_print_t *print, const char *fmt, va_list args) {
                 break;
             }
             case 'u':
-                chrs += mp_print_int(print, va_arg(args, int), 0, 10, 'a', flags, fill, width);
+                chrs += mp_print_int(print, va_arg(args, unsigned int), 0, 10, 'a', flags, fill, width);
                 break;
             case 'd':
                 chrs += mp_print_int(print, va_arg(args, int), 1, 10, 'a', flags, fill, width);
                 break;
             case 'x':
-                chrs += mp_print_int(print, va_arg(args, int), 0, 16, 'a', flags, fill, width);
+                chrs += mp_print_int(print, va_arg(args, unsigned int), 0, 16, 'a', flags, fill, width);
                 break;
             case 'X':
-                chrs += mp_print_int(print, va_arg(args, int), 0, 16, 'A', flags, fill, width);
+                chrs += mp_print_int(print, va_arg(args, unsigned int), 0, 16, 'A', flags, fill, width);
                 break;
             case 'p':
             case 'P': // don't bother to handle upcase for 'P'
diff --git a/tests/unix/extra_coverage.py.exp b/tests/unix/extra_coverage.py.exp
index 973c8bb2ee5f17aa60972e1c23c7fbe03fb39245..db282b152c72f57655f96e61134f5235266a16d4 100644
--- a/tests/unix/extra_coverage.py.exp
+++ b/tests/unix/extra_coverage.py.exp
@@ -8,6 +8,10 @@ ab abc
 false true
 (null)
 t
+-2147483648
+2147483648
+80000000
+80000000
 # vstr
 tests
 sts
diff --git a/unix/coverage.c b/unix/coverage.c
index 94d0ad4caef38a335ded768aa81d30f5b3c57329..9d53725543ec0d51c293319b7b0c050f06eb1d2c 100644
--- a/unix/coverage.c
+++ b/unix/coverage.c
@@ -22,6 +22,10 @@ STATIC mp_obj_t extra_coverage(void) {
         mp_printf(&mp_plat_print, "%b %b\n", 0, 1); // bools
         mp_printf(&mp_plat_print, "%s\n", NULL); // null string
         mp_printf(&mp_plat_print, "%t\n"); // non-format char
+        mp_printf(&mp_plat_print, "%d\n", 0x80000000); // should print signed
+        mp_printf(&mp_plat_print, "%u\n", 0x80000000); // should print unsigned
+        mp_printf(&mp_plat_print, "%x\n", 0x80000000); // should print unsigned
+        mp_printf(&mp_plat_print, "%X\n", 0x80000000); // should print unsigned
     }
 
     // vstr