diff --git a/extensions/ql-vscode/CHANGELOG.md b/extensions/ql-vscode/CHANGELOG.md
index b9378fe287d..e7c655fc385 100644
--- a/extensions/ql-vscode/CHANGELOG.md
+++ b/extensions/ql-vscode/CHANGELOG.md
@@ -7,6 +7,7 @@
 - Allow using raw LGTM project slugs for fetching LGTM databases. [#769](https://github.com/github/vscode-codeql/pull/769)
 - Better error messages when BQRS interpretation fails to produce SARIF. [#770](https://github.com/github/vscode-codeql/pull/770)
 - Implement sorting of the query history view by name, date, and results count. [#777](https://github.com/github/vscode-codeql/pull/777)
+- Add a configuration option to pass additional arguments to the CLI when running tests. [#785](https://github.com/github/vscode-codeql/pull/785)
 
 ## 1.4.3 - 22 February 2021
 
diff --git a/extensions/ql-vscode/package.json b/extensions/ql-vscode/package.json
index 8b6a783f3a8..5c765dd3576 100644
--- a/extensions/ql-vscode/package.json
+++ b/extensions/ql-vscode/package.json
@@ -182,6 +182,12 @@
           "default": "%q on %d - %s, %r result count [%t]",
           "description": "Default string for how to label query history items. %t is the time of the query, %q is the query name, %d is the database name, %r is the number of results, and %s is a status string."
         },
+        "codeQL.runningTests.additionalTestArguments": {
+          "scope": "machine",
+          "type": "array",
+          "default": [],
+          "markdownDescription": "Additional command line arguments to pass to the CLI when [running tests](https://codeql.github.com/docs/codeql-cli/manual/test-run/). This setting should be an array of strings, each containing an argument to be passed."
+        },
         "codeQL.runningTests.numberOfThreads": {
           "scope": "window",
           "type": "integer",
diff --git a/extensions/ql-vscode/src/cli.ts b/extensions/ql-vscode/src/cli.ts
index e4548555ad1..947a229828f 100644
--- a/extensions/ql-vscode/src/cli.ts
+++ b/extensions/ql-vscode/src/cli.ts
@@ -509,12 +509,12 @@ export class CodeQLCliServer implements Disposable {
     testPaths: string[], workspaces: string[], options: TestRunOptions
   ): AsyncGenerator<TestCompleted, void, unknown> {
 
-    const subcommandArgs = [
+    const subcommandArgs = this.cliConfig.additionalTestArguments.concat([
       '--additional-packs', workspaces.join(path.delimiter),
       '--threads',
       this.cliConfig.numberTestThreads.toString(),
       ...testPaths
-    ];
+    ]);
 
     for await (const event of await this.runAsyncCodeQlCliCommand<TestCompleted>(['test', 'run'],
       subcommandArgs, 'Run CodeQL Tests', options.cancellationToken, options.logger)) {
diff --git a/extensions/ql-vscode/src/config.ts b/extensions/ql-vscode/src/config.ts
index 885bf56bc6b..598c3f6f84e 100644
--- a/extensions/ql-vscode/src/config.ts
+++ b/extensions/ql-vscode/src/config.ts
@@ -81,6 +81,7 @@ const DEBUG_SETTING = new Setting('debug', RUNNING_QUERIES_SETTING);
 const RUNNING_TESTS_SETTING = new Setting('runningTests', ROOT_SETTING);
 const RESULTS_DISPLAY_SETTING = new Setting('resultsDisplay', ROOT_SETTING);
 
+export const ADDITIONAL_TEST_ARGUMENTS_SETTING = new Setting('additionalTestArguments', RUNNING_TESTS_SETTING);
 export const NUMBER_OF_TEST_THREADS_SETTING = new Setting('numberOfThreads', RUNNING_TESTS_SETTING);
 export const MAX_QUERIES = new Setting('maxQueries', RUNNING_QUERIES_SETTING);
 export const AUTOSAVE_SETTING = new Setting('autoSave', RUNNING_QUERIES_SETTING);
@@ -108,9 +109,10 @@ export interface QueryHistoryConfig {
   onDidChangeConfiguration: Event<void>;
 }
 
-const CLI_SETTINGS = [NUMBER_OF_TEST_THREADS_SETTING, NUMBER_OF_THREADS_SETTING];
+const CLI_SETTINGS = [ADDITIONAL_TEST_ARGUMENTS_SETTING, NUMBER_OF_TEST_THREADS_SETTING, NUMBER_OF_THREADS_SETTING];
 
 export interface CliConfig {
+  additionalTestArguments: string[];
   numberTestThreads: number;
   numberThreads: number;
   onDidChangeConfiguration?: Event<void>;
@@ -243,6 +245,9 @@ export class QueryHistoryConfigListener extends ConfigListener implements QueryH
 }
 
 export class CliConfigListener extends ConfigListener implements CliConfig {
+  public get additionalTestArguments(): string[] {
+    return ADDITIONAL_TEST_ARGUMENTS_SETTING.getValue();
+  }
 
   public get numberTestThreads(): number {
     return NUMBER_OF_TEST_THREADS_SETTING.getValue();