diff --git a/src/goDebugConfiguration.ts b/src/goDebugConfiguration.ts
index bf2b1eb..dc6055c 100644
--- a/src/goDebugConfiguration.ts
+++ b/src/goDebugConfiguration.ts
@@ -141,6 +141,15 @@
 			debugConfiguration['type'] = this.defaultDebugAdapterType;
 		}
 
+		if (!debugConfiguration['mode']) {
+			if (debugConfiguration.request === 'launch') {
+				// 'auto' will decide mode by checking file extensions later
+				debugConfiguration['mode'] = 'auto';
+			} else if (debugConfiguration.request === 'attach') {
+				debugConfiguration['mode'] = 'local';
+			}
+		}
+
 		debugConfiguration['packagePathToGoModPathMap'] = packagePathToGoModPathMap;
 
 		const goConfig = getGoConfig(folder && folder.uri);
diff --git a/test/integration/goDebugConfiguration.test.ts b/test/integration/goDebugConfiguration.test.ts
index ad382ca..5f63b8c 100644
--- a/test/integration/goDebugConfiguration.test.ts
+++ b/test/integration/goDebugConfiguration.test.ts
@@ -920,3 +920,45 @@
 		assert.strictEqual(resolvedConfig['debugAdapter'], want);
 	});
 });
+
+suite('Debug Configuration Infers Default Mode Property', () => {
+	const debugConfigProvider = new GoDebugConfigurationProvider();
+	test("default mode for launch requests and test Go programs should be 'test'", () => {
+		const config = {
+			name: 'Launch',
+			type: 'go',
+			request: 'launch',
+			program: '/path/to/main_test.go'
+		};
+
+		debugConfigProvider.resolveDebugConfiguration(undefined, config);
+		const resolvedConfig = config as any;
+		assert.strictEqual(resolvedConfig['mode'], 'test');
+	});
+
+	test("default mode for launch requests and non-test Go programs should be 'debug'", () => {
+		const config = {
+			name: 'Launch',
+			type: 'go',
+			request: 'launch',
+			program: '/path/to/main.go'
+		};
+
+		debugConfigProvider.resolveDebugConfiguration(undefined, config);
+		const resolvedConfig = config as any;
+		assert.strictEqual(resolvedConfig['mode'], 'debug');
+	});
+
+	test("default mode for attach requests should be 'local'", () => {
+		const config = {
+			name: 'Attach',
+			type: 'go',
+			request: 'attach',
+			program: '/path/to/main.go'
+		};
+
+		debugConfigProvider.resolveDebugConfiguration(undefined, config);
+		const resolvedConfig = config as any;
+		assert.strictEqual(resolvedConfig['mode'], 'local');
+	});
+});