diff --git a/doc/usage/cmdline.rst b/doc/usage/cmdline.rst
index 2d5127c..88f18c9 100644
--- a/doc/usage/cmdline.rst
+++ b/doc/usage/cmdline.rst
@@ -85,3 +85,9 @@
   => pmic write 2 0177
   => pmic read 2
   0x02: 0x00007f
+
+It is possible to use a `0x` prefix to use a hex value if that is more
+convenient::
+
+  => i2c speed 0x30000
+  Setting bus speed to 196608 Hz
diff --git a/include/vsprintf.h b/include/vsprintf.h
index debf977..83d187e 100644
--- a/include/vsprintf.h
+++ b/include/vsprintf.h
@@ -22,8 +22,12 @@
  * the end these are ignored. In the worst case, if all characters are invalid,
  * 0 is returned
  *
- * If @base is 0, octal or hex prefixes are supported (e.g. 0777, 0x123) to
- * select a particular base. By default decimal is used.
+ * A hex prefix is supported (e.g. 0x123) regardless of the value of @base.
+ * If found, the base is set to hex (16).
+ *
+ * If @base is 0:
+ *    - an octal '0' prefix (e.g. 0777) sets the base to octal (8).
+ *    - otherwise the base defaults to decimal (10).
  */
 ulong simple_strtoul(const char *cp, char **endp, unsigned int base);
 
@@ -71,8 +75,12 @@
  *
  * echo will append a newline to the tail.
  *
- * If @base is 0, octal or hex prefixes are supported (e.g. 0777, 0x123) to
- * select a particular base. By default decimal is used.
+ * A hex prefix is supported (e.g. 0x123) regardless of the value of @base.
+ * If found, the base is set to hex (16).
+ *
+ * If @base is 0:
+ *    - an octal '0' prefix (e.g. 0777) sets the base to octal (8).
+ *    - otherwise the base defaults to decimal (10).
  *
  * Copied this function from Linux 2.6.38 commit ID:
  * 521cb40b0c44418a4fd36dc633f575813d59a43d
diff --git a/lib/strto.c b/lib/strto.c
index b056b20..7bba1e3 100644
--- a/lib/strto.c
+++ b/lib/strto.c
@@ -14,19 +14,25 @@
 #include <linux/ctype.h>
 
 /* from lib/kstrtox.c */
-static const char *_parse_integer_fixup_radix(const char *s, unsigned int *base)
+static const char *_parse_integer_fixup_radix(const char *s, uint *basep)
 {
-	if (*base == 0) {
-		if (s[0] == '0') {
-			if (tolower(s[1]) == 'x')
-				*base = 16;
-			else
-				*base = 8;
-		} else
-			*base = 10;
+	/* Look for a 0x prefix */
+	if (s[0] == '0') {
+		int ch = tolower(s[1]);
+
+		if (ch == 'x') {
+			*basep = 16;
+			s += 2;
+		} else if (!*basep) {
+			/* Only select octal if we don't have a base */
+			*basep = 8;
+		}
 	}
-	if (*base == 16 && s[0] == '0' && tolower(s[1]) == 'x')
-		s += 2;
+
+	/* Use decimal by default */
+	if (!*basep)
+		*basep = 10;
+
 	return s;
 }
 
diff --git a/test/str_ut.c b/test/str_ut.c
index 0d1bf39..d2840d5 100644
--- a/test/str_ut.c
+++ b/test/str_ut.c
@@ -89,7 +89,7 @@
 		ut_assertok(run_strtoul(uts, str2, 10, 1099, 4, upper));
 		ut_assertok(run_strtoul(uts, str2, 16, 0x1099ab, 6, upper));
 		ut_assertok(run_strtoul(uts, str3, 16, 0xb, 3, upper));
-		ut_assertok(run_strtoul(uts, str3, 10, 0, 1, upper));
+		ut_assertok(run_strtoul(uts, str3, 10, 0xb, 3, upper));
 
 		/* Octal */
 		ut_assertok(run_strtoul(uts, str6, 0, 63, 3, upper));
@@ -144,7 +144,7 @@
 		ut_assertok(run_strtoull(uts, str2, 10, 1099, 4, upper));
 		ut_assertok(run_strtoull(uts, str2, 16, 0x1099ab, 6, upper));
 		ut_assertok(run_strtoull(uts, str3, 16, 0xb, 3, upper));
-		ut_assertok(run_strtoull(uts, str3, 10, 0, 1, upper));
+		ut_assertok(run_strtoull(uts, str3, 10, 0xb, 3, upper));
 
 		/* Octal */
 		ut_assertok(run_strtoull(uts, str6, 0, 63, 3, upper));