diff --git a/services/core/java/com/android/server/pm/PackageInstallerSession.java b/services/core/java/com/android/server/pm/PackageInstallerSession.java
index 7cc49fd7aab24..542948491dc8c 100644
--- a/services/core/java/com/android/server/pm/PackageInstallerSession.java
+++ b/services/core/java/com/android/server/pm/PackageInstallerSession.java
@@ -2260,6 +2260,21 @@ public class PackageInstallerSession extends IPackageInstallerSession.Stub {
                     return;
                 }
             }
+
+            if (!params.isStaged) {
+                // For non-staged APEX installs also check if there is a staged session that
+                // contains the same APEX. If that's the case, we should fail this session.
+                synchronized (mLock) {
+                    int sessionId = mStagingManager.getSessionIdByPackageName(mPackageName);
+                    if (sessionId != -1) {
+                        onSessionValidationFailure(
+                                PackageManager.INSTALL_FAILED_VERIFICATION_FAILURE,
+                                "Staged session " + sessionId + " already contains "
+                                        + mPackageName);
+                        return;
+                    }
+                }
+            }
         }
 
         if (params.isStaged) {
diff --git a/services/core/java/com/android/server/pm/StagingManager.java b/services/core/java/com/android/server/pm/StagingManager.java
index 4ac5be2ec7c7c..bdbcb277e8d66 100644
--- a/services/core/java/com/android/server/pm/StagingManager.java
+++ b/services/core/java/com/android/server/pm/StagingManager.java
@@ -777,6 +777,26 @@ public class StagingManager {
         }
     }
 
+    /**
+     * Returns id of a committed and non-finalized stated session that contains same
+     * {@code packageName}, or {@code -1} if no sessions have this {@code packageName} staged.
+     */
+    int getSessionIdByPackageName(@NonNull String packageName) {
+        synchronized (mStagedSessions) {
+            for (int i = 0; i < mStagedSessions.size(); i++) {
+                StagedSession stagedSession = mStagedSessions.valueAt(i);
+                if (!stagedSession.isCommitted() || stagedSession.isDestroyed()
+                        || stagedSession.isInTerminalState()) {
+                    continue;
+                }
+                if (stagedSession.getPackageName().equals(packageName)) {
+                    return stagedSession.sessionId();
+                }
+            }
+        }
+        return -1;
+    }
+
     @VisibleForTesting
     void createSession(@NonNull StagedSession sessionInfo) {
         synchronized (mStagedSessions) {
diff --git a/services/tests/mockingservicestests/src/com/android/server/pm/StagingManagerTest.java b/services/tests/mockingservicestests/src/com/android/server/pm/StagingManagerTest.java
index f91cb2801bc12..521be70df633f 100644
--- a/services/tests/mockingservicestests/src/com/android/server/pm/StagingManagerTest.java
+++ b/services/tests/mockingservicestests/src/com/android/server/pm/StagingManagerTest.java
@@ -459,6 +459,66 @@ public class StagingManagerTest {
         assertThat(apkSession.getErrorMessage()).isEqualTo("Another apex session failed");
     }
 
+    @Test
+    public void getSessionIdByPackageName() throws Exception {
+        FakeStagedSession session = new FakeStagedSession(239);
+        session.setCommitted(true);
+        session.setSessionReady();
+        session.setPackageName("com.foo");
+
+        mStagingManager.createSession(session);
+        assertThat(mStagingManager.getSessionIdByPackageName("com.foo")).isEqualTo(239);
+    }
+
+    @Test
+    public void getSessionIdByPackageName_appliedSession_ignores() throws Exception {
+        FakeStagedSession session = new FakeStagedSession(37);
+        session.setCommitted(true);
+        session.setSessionApplied();
+        session.setPackageName("com.foo");
+
+        mStagingManager.createSession(session);
+        assertThat(mStagingManager.getSessionIdByPackageName("com.foo")).isEqualTo(-1);
+    }
+
+    @Test
+    public void getSessionIdByPackageName_failedSession_ignores() throws Exception {
+        FakeStagedSession session = new FakeStagedSession(73);
+        session.setCommitted(true);
+        session.setSessionFailed(1, "whatevs");
+        session.setPackageName("com.foo");
+
+        mStagingManager.createSession(session);
+        assertThat(mStagingManager.getSessionIdByPackageName("com.foo")).isEqualTo(-1);
+    }
+
+    @Test
+    public void getSessionIdByPackageName_destroyedSession_ignores() throws Exception {
+        FakeStagedSession session = new FakeStagedSession(23);
+        session.setCommitted(true);
+        session.setDestroyed(true);
+        session.setPackageName("com.foo");
+
+        mStagingManager.createSession(session);
+        assertThat(mStagingManager.getSessionIdByPackageName("com.foo")).isEqualTo(-1);
+    }
+
+    @Test
+    public void getSessionIdByPackageName_noSessions() throws Exception {
+        assertThat(mStagingManager.getSessionIdByPackageName("com.foo")).isEqualTo(-1);
+    }
+
+    @Test
+    public void getSessionIdByPackageName_noSessionHasThisPackage() throws Exception {
+        FakeStagedSession session = new FakeStagedSession(37);
+        session.setCommitted(true);
+        session.setSessionApplied();
+        session.setPackageName("com.foo");
+
+        mStagingManager.createSession(session);
+        assertThat(mStagingManager.getSessionIdByPackageName("com.bar")).isEqualTo(-1);
+    }
+
     private StagingManager.StagedSession createSession(int sessionId, String packageName,
             long committedMillis) {
         PackageInstaller.SessionParams params = new PackageInstaller.SessionParams(
diff --git a/tests/StagedInstallTest/Android.bp b/tests/StagedInstallTest/Android.bp
index 1aa04996f6827..cac14a72a7061 100644
--- a/tests/StagedInstallTest/Android.bp
+++ b/tests/StagedInstallTest/Android.bp
@@ -32,6 +32,7 @@ android_test_helper_app {
     test_suites: ["general-tests"],
     java_resources: [
         ":com.android.apex.apkrollback.test_v2",
+        ":StagedInstallTestApexV2",
         ":StagedInstallTestApexV2_WrongSha",
         ":test.rebootless_apex_v1",
         ":test.rebootless_apex_v2",
diff --git a/tests/StagedInstallTest/app/src/com/android/tests/stagedinstallinternal/StagedInstallInternalTest.java b/tests/StagedInstallTest/app/src/com/android/tests/stagedinstallinternal/StagedInstallInternalTest.java
index 60585e84d4ef5..4684f0182d034 100644
--- a/tests/StagedInstallTest/app/src/com/android/tests/stagedinstallinternal/StagedInstallInternalTest.java
+++ b/tests/StagedInstallTest/app/src/com/android/tests/stagedinstallinternal/StagedInstallInternalTest.java
@@ -57,6 +57,9 @@ public class StagedInstallInternalTest {
     private static final TestApp APEX_WRONG_SHA_V2 = new TestApp(
             "ApexWrongSha2", SHIM_APEX_PACKAGE_NAME, 2, /* isApex= */ true,
             "com.android.apex.cts.shim.v2_wrong_sha.apex");
+    private static final TestApp APEX_V2 = new TestApp(
+            "ApexV2", SHIM_APEX_PACKAGE_NAME, 2, /* isApex= */ true,
+            "com.android.apex.cts.shim.v2.apex");
 
     private File mTestStateFile = new File(
             InstrumentationRegistry.getInstrumentation().getContext().getFilesDir(),
@@ -388,6 +391,19 @@ public class StagedInstallInternalTest {
         }
     }
 
+    @Test
+    public void testRebootlessUpdate_hasStagedSessionWithSameApex_fails() throws Exception {
+        assertThat(InstallUtils.getInstalledVersion(SHIM_APEX_PACKAGE_NAME)).isEqualTo(1);
+
+        int sessionId = Install.single(APEX_V2).setStaged().commit();
+        assertSessionReady(sessionId);
+        InstallUtils.commitExpectingFailure(
+                AssertionError.class,
+                "Staged session " + sessionId + " already contains " + SHIM_APEX_PACKAGE_NAME,
+                Install.single(APEX_V2));
+
+    }
+
     private static void assertSessionApplied(int sessionId) {
         assertSessionState(sessionId, (session) -> {
             assertThat(session.isStagedSessionApplied()).isTrue();
diff --git a/tests/StagedInstallTest/src/com/android/tests/stagedinstallinternal/host/StagedInstallInternalTest.java b/tests/StagedInstallTest/src/com/android/tests/stagedinstallinternal/host/StagedInstallInternalTest.java
index c6b6aabb74ace..5021009f65ae8 100644
--- a/tests/StagedInstallTest/src/com/android/tests/stagedinstallinternal/host/StagedInstallInternalTest.java
+++ b/tests/StagedInstallTest/src/com/android/tests/stagedinstallinternal/host/StagedInstallInternalTest.java
@@ -470,6 +470,14 @@ public class StagedInstallInternalTest extends BaseHostJUnit4Test {
         runPhase("testRebootlessUpdates");
     }
 
+    @Test
+    public void testRebootlessUpdate_hasStagedSessionWithSameApex_fails() throws Exception {
+        assumeTrue("Device does not support updating APEX",
+                mHostUtils.isApexUpdateSupported());
+
+        runPhase("testRebootlessUpdate_hasStagedSessionWithSameApex_fails");
+    }
+
     private List<String> getStagingDirectories() throws DeviceNotAvailableException {
         String baseDir = "/data/app-staging";
         try {