diff --git a/types/codemirror/index.d.ts b/types/codemirror/index.d.ts
index 788fe591eb..6acbabd2c1 100644
--- a/types/codemirror/index.d.ts
+++ b/types/codemirror/index.d.ts
@@ -1224,7 +1224,7 @@ declare namespace CodeMirror {
 
     interface CommandActions {
         /** Select the whole content of the editor. */
-        selectAll(): void;
+        selectAll(cm: CodeMirror.Editor): void;
 
         /** When multiple selections are present, this deselects all but the primary selection. */
         singleSelection(cm: CodeMirror.Editor): void;
diff --git a/types/codemirror/test/index.ts b/types/codemirror/test/index.ts
index 649361ae99..c9ccd13b29 100644
--- a/types/codemirror/test/index.ts
+++ b/types/codemirror/test/index.ts
@@ -101,5 +101,4 @@ widget2.clear();
 htmlElement1.remove();
 htmlElement2.remove();
 
-CodeMirror.commands.selectAll();
 CodeMirror.commands.newlineAndIndent(myCodeMirror);