diff --git a/geozero/src/lib.rs b/geozero/src/lib.rs
index 42b6670f..0374efcd 100644
--- a/geozero/src/lib.rs
+++ b/geozero/src/lib.rs
@@ -30,7 +30,7 @@
 //! | MVT           | [mvt::tile::Feature]                                                                                                     | XY         | [mvt::tile::Layer]                                                                   | [ToMvt]             | [MvtWriter](mvt::MvtWriter)                     |
 //! | SVG           | -                                                                                                                        | XY         | -                                                                                    | [ToSvg]             | [SvgWriter](svg::SvgWriter)                     |
 //! | WKB           | [Wkb](wkb::Wkb), [Ewkb](wkb::Ewkb), [GpkgWkb](wkb::GpkgWkb), [SpatiaLiteWkb](wkb::SpatiaLiteWkb), [MySQL](wkb::MySQLWkb) | XYZM       | -                                                                                    | [ToWkb]             | [WkbWriter](wkb::WkbWriter)                     |
-//! | WKT           | [wkt::WktStr], [wkt::WktString], [wkt::EwktStr], [wkt::EwktString]                                                       | XYZM       | [wkt::WktReader], [wkt::WktStr], [wkt::WktString], [wkt::EwktStr], [wkt::EwktString] | [ToWkt]             | [WktWriter](wkt::WktWriter)                     |
+//! | WKT           | [wkt::WktStr], [wkt::WktString], [wkt::EwktStr], [wkt::EwktString]                                                       | XYZM (ZM write-only)       | [wkt::WktReader], [wkt::WktStr], [wkt::WktString], [wkt::EwktStr], [wkt::EwktString] | [ToWkt]             | [WktWriter](wkt::WktWriter)                     |
 
 #![warn(clippy::uninlined_format_args)]
 #![allow(
diff --git a/geozero/src/wkt/wkt_reader.rs b/geozero/src/wkt/wkt_reader.rs
index fdefd256..221684d4 100644
--- a/geozero/src/wkt/wkt_reader.rs
+++ b/geozero/src/wkt/wkt_reader.rs
@@ -450,3 +450,26 @@ mod test {
         }
     }
 }
+
+#[cfg(all(test, feature = "with-geojson"))]
+mod test_3d {
+    use crate::ToJson;
+
+    use super::*;
+
+    #[test]
+    #[ignore = "3d WKT not supported"]
+    fn point_3d() {
+        let wkt = Wkt("POINT Z(1.0 2.0 3.0)");
+        let actual = wkt.to_json().unwrap();
+        dbg!(actual);
+    }
+
+    #[test]
+    #[ignore = "M-value WKT not supported"]
+    fn point_m() {
+        let wkt = Wkt("POINT M(1.0 2.0 3.0)");
+        let actual = wkt.to_json().unwrap();
+        dbg!(actual);
+    }
+}