diff --git a/packages/app-gnome/src/widgets/source-view.ts b/packages/app-gnome/src/widgets/source-view.ts
index 5f75ab68..565adcc1 100644
--- a/packages/app-gnome/src/widgets/source-view.ts
+++ b/packages/app-gnome/src/widgets/source-view.ts
@@ -262,6 +262,7 @@ export class SourceView extends Adw.Bin implements SourceViewWidget {
    */
   public set editable(value: boolean) {
     this._sourceView.set_editable(value);
+    this.updateCurrentLineHighlight();
   }
 
   /**
@@ -315,7 +316,7 @@ export class SourceView extends Adw.Bin implements SourceViewWidget {
         this.copyClipboardSignalId = undefined;
       }
     }
-    this._sourceView.highlight_current_line = true;
+    this.updateCurrentLineHighlight();
   }
 
   /**
@@ -800,6 +801,14 @@ export class SourceView extends Adw.Bin implements SourceViewWidget {
     this.events.dispatch("changed", { code: this.code });
   }
 
+  /**
+   * Highlight the cursor line only while editing: in read-only code blocks
+   * the idle cursor (sitting at the last line) would look like a selection.
+   */
+  private updateCurrentLineHighlight() {
+    this._sourceView.highlight_current_line = this._sourceView.editable;
+  }
+
   /**
    * Update the style of the source view.
    * Used internally to update the style of the source view when the theme changes.
@@ -812,7 +821,7 @@ export class SourceView extends Adw.Bin implements SourceViewWidget {
       scheme = this.schemeManager.get_scheme(isDark ? "Adwaita-dark" : "Adwaita");
     }
     if (scheme) this.buffer.set_style_scheme(scheme);
-    this._sourceView.set_highlight_current_line(true);
+    this.updateCurrentLineHighlight();
   }
 
   /**
diff --git a/packages/learn/tsx/components/gtk/gtk-code.compontent.tsx b/packages/learn/tsx/components/gtk/gtk-code.compontent.tsx
index d6c8ede4..c734c960 100644
--- a/packages/learn/tsx/components/gtk/gtk-code.compontent.tsx
+++ b/packages/learn/tsx/components/gtk/gtk-code.compontent.tsx
@@ -160,7 +160,9 @@ export class GtkCode extends GtkWidget<GtkCodeProps> {
    */
   protected parseAttributes(props: GtkCodeProps): Partial<GtkCodeProps> {
     let language = props.language || "";
-    let readonly = props.readonly || false;
+    // MDX code blocks are documentation, so they always render read-only;
+    // the only editable SourceView is the editor itself
+    let readonly = props.readonly ?? true;
     let copyable = props.copyable || false;
     let unselectable = props.unselectable || false;
     let noLineNumbers = props.noLineNumbers || false;