diff --git a/types/atom/atom-tests.ts b/types/atom/atom-tests.ts
index 5fc92880f4..fbd5f6d0d8 100644
--- a/types/atom/atom-tests.ts
+++ b/types/atom/atom-tests.ts
@@ -1459,6 +1459,14 @@ function testPackageManager() {
 
     bool = atom.packages.isPackageDisabled("Test");
 
+    // Activating and deactivating packages
+    atom.packages.activatePackage("Test").then((activePack) => {
+        pack = activePack;
+    });
+    atom.packages.deactivatePackage("Test", true).then(() => {
+        // package is deactivated
+    });
+
     // Accessing active packages
     packs = atom.packages.getActivePackages();
 
diff --git a/types/atom/index.d.ts b/types/atom/index.d.ts
index a261661144..f83f751657 100644
--- a/types/atom/index.d.ts
+++ b/types/atom/index.d.ts
@@ -4111,6 +4111,9 @@ export interface PackageManager {
     /** Activate a single package by name or path. */
     activatePackage(nameOrPath: string): Promise<Package>;
 
+    /** Deactivate a single package by name or path. */
+    deactivatePackage(nameOrPath: string, suppressSerialization?: boolean): Promise<void>;
+
     /** Triggers the given package activation hook. */
     triggerActivationHook(hook: string): void;