diff --git a/src/ol/source/Tile.js b/src/ol/source/Tile.js
index 901386fa8a..71772e8242 100644
--- a/src/ol/source/Tile.js
+++ b/src/ol/source/Tile.js
@@ -19,7 +19,7 @@ import {scale as scaleSize, toSize} from '../size.js';
  * @property {import("./Source.js").AttributionLike} [attributions]
  * @property {boolean} [attributionsCollapsible=true] Attributions are collapsible.
  * @property {number} [cacheSize]
- * @property {boolean} [opaque]
+ * @property {boolean} [opaque=false]
  * @property {number} [tilePixelRatio]
  * @property {import("../proj.js").ProjectionLike} [projection]
  * @property {import("./State.js").default} [state]
diff --git a/src/ol/source/TileImage.js b/src/ol/source/TileImage.js
index ba100b94af..ff60cab9f8 100644
--- a/src/ol/source/TileImage.js
+++ b/src/ol/source/TileImage.js
@@ -23,7 +23,7 @@ import {getUid} from '../util.js';
  * you must provide a `crossOrigin` value if you want to access pixel data with the Canvas renderer.
  * See https://developer.mozilla.org/en-US/docs/Web/HTML/CORS_enabled_image for more detail.
  * @property {boolean} [imageSmoothing=true] Enable image smoothing.
- * @property {boolean} [opaque=true] Whether the layer is opaque.
+ * @property {boolean} [opaque=false] Whether the layer is opaque.
  * @property {import("../proj.js").ProjectionLike} [projection] Projection. Default is the view projection.
  * @property {number} [reprojectionErrorThreshold=0.5] Maximum allowed reprojection error (in pixels).
  * Higher values can increase reprojection performance, but decrease precision.
diff --git a/src/ol/source/UrlTile.js b/src/ol/source/UrlTile.js
index f48e20cc6f..28d6d5a3c7 100644
--- a/src/ol/source/UrlTile.js
+++ b/src/ol/source/UrlTile.js
@@ -13,7 +13,7 @@ import {getUid} from '../util.js';
  * @property {import("./Source.js").AttributionLike} [attributions]
  * @property {boolean} [attributionsCollapsible=true] Attributions are collapsible.
  * @property {number} [cacheSize]
- * @property {boolean} [opaque]
+ * @property {boolean} [opaque=false]
  * @property {import("../proj.js").ProjectionLike} [projection]
  * @property {import("./State.js").default} [state]
  * @property {import("../tilegrid/TileGrid.js").default} [tileGrid]
diff --git a/src/ol/source/XYZ.js b/src/ol/source/XYZ.js
index 7ef173591f..80167f7c24 100644
--- a/src/ol/source/XYZ.js
+++ b/src/ol/source/XYZ.js
@@ -14,7 +14,7 @@ import {createXYZ, extentFromProjection} from '../tilegrid.js';
  * you must provide a `crossOrigin` value if you want to access pixel data with the Canvas renderer.
  * See https://developer.mozilla.org/en-US/docs/Web/HTML/CORS_enabled_image for more detail.
  * @property {boolean} [imageSmoothing=true] Enable image smoothing.
- * @property {boolean} [opaque=true] Whether the layer is opaque.
+ * @property {boolean} [opaque=false] Whether the layer is opaque.
  * @property {import("../proj.js").ProjectionLike} [projection='EPSG:3857'] Projection.
  * @property {number} [reprojectionErrorThreshold=0.5] Maximum allowed reprojection error (in pixels).
  * Higher values can increase reprojection performance, but decrease precision.