diff --git a/man2/ioctl_userfaultfd.2 b/man2/ioctl_userfaultfd.2
index 926b4d376..4870f566a 100644
--- a/man2/ioctl_userfaultfd.2
+++ b/man2/ioctl_userfaultfd.2
@@ -240,6 +240,14 @@ field was zero.
 There is no mapping in the specified address range.
 .TP
 .B EINVAL
+.I range.start
+or
+.I range.len
+is not a multiple of the system page size; or,
+.I range.len
+is zero; or these fields are otherwise invalid.
+.TP
+.B EINVAL
 There as an incompatible mapping in the specified address range.
 .\" FIXME What does "incompatible" mean?
 .\"
@@ -266,7 +274,9 @@ or the
 .I len
 field of the
 .I ufdio_range
-structure was not a multiple of the system page size.
+structure was not a multiple of the system page size; or the
+.I len
+field was zero; or these fields were otherwise invalid.
 .TP
 .B EINVAL
 There as an incompatible mapping in the specified address range.
@@ -436,8 +446,9 @@ Either
 .I range.start
 or
 .I range.len
-was not a multiple of the system page size,
-or the range specified was invalid.
+was not a multiple of the system page size; or
+.I range.len
+was zero; or the range specified was invalid.
 .TP
 .B EINVAL
 An invalid bit was specified in the
@@ -464,13 +475,15 @@ is set to indicate the cause of the error.
 Possible errors include:
 .TP
 .B EINVAL
-Either the
+The
 .I start
 or the
 .I len
 field of the
 .I ufdio_range
-structure was not a multiple of the system page size.
+structure was not a multiple of the system page size; or
+.I len
+was zero; or the specified range was otherwise invalid.
 .SH RETURN VALUE
 See descriptions of the individual operations, above.
 .SH ERRORS