diff --git a/integration/vscode/ada/src/taskProviders.ts b/integration/vscode/ada/src/taskProviders.ts
index 4154f2b03..68edd44b9 100644
--- a/integration/vscode/ada/src/taskProviders.ts
+++ b/integration/vscode/ada/src/taskProviders.ts
@@ -21,6 +21,7 @@ import * as vscode from 'vscode';
 import { SymbolKind } from 'vscode';
 import { adaExtState } from './extension';
 import { AdaMain, getAdaMains, getProjectFile, getSymbols } from './helpers';
+import path from 'path';
 
 export const ADA_TASK_TYPE = 'ada';
 
@@ -691,8 +692,15 @@ async function buildFullCommandLine(
 
     if (taskDef.configuration.kind == 'runMain') {
         if (adaMain) {
-            // Append the run of the main executable
-            cmd.push(adaMain.execRelPath());
+            // Append the main executable's relative path, prepending './'
+            // (or '.\\' on Windows) when needed, to make sure it's executable from
+            // a shell.
+            let execRelPath = adaMain.execRelPath();
+            if (!execRelPath.includes(path.sep)) {
+                execRelPath = '.' + path.sep + execRelPath;
+            }
+
+            cmd.push(execRelPath);
             if (taskDef.configuration.mainArgs) {
                 cmd = cmd.concat(taskDef.configuration.mainArgs);
             }
diff --git a/integration/vscode/ada/test/suite/general/tasks.test.ts b/integration/vscode/ada/test/suite/general/tasks.test.ts
index eb02c1976..8206f608a 100644
--- a/integration/vscode/ada/test/suite/general/tasks.test.ts
+++ b/integration/vscode/ada/test/suite/general/tasks.test.ts
@@ -11,6 +11,7 @@ import {
     getSelectedRegion,
 } from '../../../src/taskProviders';
 import { activate } from '../utils';
+import path from 'path';
 
 suite('GPR Tasks Provider', function () {
     let projectPath: string;
@@ -244,6 +245,34 @@ ada: Build and run main - src/test.adb - kind: buildAndRunMain`.trim();
         assert.equal(execStatus, 0);
     });
 
+    /**
+     * Check that the 'buildAndRunMain' task works fine with projects that
+     * do not explicitly define an object directory.
+     */
+    test('buildAndRunMain task without object directory', async () => {
+        // Load a custom project that does not define any object dir by
+        // changing the 'ada.projectFile' setting.
+        const initialProjectFile = vscode.workspace.getConfiguration().get('ada.projectFile');
+        try {
+            await vscode.workspace
+                .getConfiguration()
+                .update(
+                    'ada.projectFile',
+                    'default_without_obj_dir' + path.sep + 'default_without_obj_dir.gpr'
+                );
+            const adaTasks = await vscode.tasks.fetchTasks({ type: 'ada' });
+            const task = adaTasks.find((v) => v.name == 'Build and run main - src/main1.adb');
+            assert(task);
+
+            // Check that the executable has been ran correctly
+            const execStatus: number | undefined = await runTaskAndGetResult(task);
+            assert.equal(execStatus, 0);
+        } finally {
+            // Reset the 'ada.projectFile' setting.
+            await vscode.workspace.getConfiguration().update('ada.projectFile', initialProjectFile);
+        }
+    });
+
     /**
      * Test that buildAndRunMain fails when configured with non-existing tasks
      */
diff --git a/integration/vscode/ada/test/workspaces/general/default_without_obj_dir/default_without_obj_dir.gpr b/integration/vscode/ada/test/workspaces/general/default_without_obj_dir/default_without_obj_dir.gpr
new file mode 100644
index 000000000..607f6e091
--- /dev/null
+++ b/integration/vscode/ada/test/workspaces/general/default_without_obj_dir/default_without_obj_dir.gpr
@@ -0,0 +1,18 @@
+project Default_Without_Obj_Dir is
+
+    Tools_Mains :=
+     ("main1.adb",
+      "test.adb");
+
+    for Source_Dirs use ("../src/**");
+    for Main use Tools_Mains;
+
+    package Builder is
+      for Executable ("main1.adb") use "main1exec";
+   end Builder;
+
+   package Compiler is
+      for Default_Switches ("Ada") use ("-g", "-O0");
+   end Compiler;
+
+end Default_Without_Obj_Dir;