diff --git a/types/openlayers/index.d.ts b/types/openlayers/index.d.ts
index 9c1ebe262f..9dc5461f5e 100644
--- a/types/openlayers/index.d.ts
+++ b/types/openlayers/index.d.ts
@@ -7545,7 +7545,7 @@ export namespace proj {
      * Projection units: `'degrees'`, `'ft'`, `'m'`, `'pixels'`, `'tile-pixels'` or
      * `'us-ft'`.
      */
-    type Units = "degress" | "ft" | "m" | "pixels" | "tile-pixels" | "us-ft";
+    type Units = "degrees" | "ft" | "m" | "pixels" | "tile-pixels" | "us-ft";
 
     /**
      * Meters per unit lookup table.
diff --git a/types/openlayers/openlayers-tests.ts b/types/openlayers/openlayers-tests.ts
index e54c496e71..58f9c5e4ad 100644
--- a/types/openlayers/openlayers-tests.ts
+++ b/types/openlayers/openlayers-tests.ts
@@ -636,6 +636,13 @@ projection.setGetPointResolution(getPointResolutionFn);
 projection.setGlobal(booleanValue);
 projection.setWorldExtent(extent);
 
+units = 'degrees';
+units = 'ft';
+units = 'm';
+units = 'pixels';
+units = 'tile-pixels';
+units = 'us-ft';
+
 //
 // ol.Map
 //