diff --git a/framework-t/src/android/net/IpSecAlgorithm.java b/framework-t/src/android/net/IpSecAlgorithm.java
index a39a80d..aac6f79 100644
--- a/framework-t/src/android/net/IpSecAlgorithm.java
+++ b/framework-t/src/android/net/IpSecAlgorithm.java
@@ -21,6 +21,7 @@
 import android.os.Build;
 import android.os.Parcel;
 import android.os.Parcelable;
+import android.os.SystemProperties;
 
 import com.android.internal.annotations.VisibleForTesting;
 
@@ -351,8 +352,11 @@
             }
         }
 
+        // T introduced calculated property 'ro.vendor.api_level',
+        // which is the API level of the VSR that the device must conform to.
+        int vendorApiLevel = SystemProperties.getInt("ro.vendor.api_level", 10000);
         for (Entry<String, Integer> entry : ALGO_TO_REQUIRED_FIRST_SDK.entrySet()) {
-            if (Build.VERSION.DEVICE_INITIAL_SDK_INT >= entry.getValue()) {
+            if (vendorApiLevel >= entry.getValue()) {
                 enabledAlgos.add(entry.getKey());
             }
         }
diff --git a/tests/unit/java/android/net/IpSecAlgorithmTest.java b/tests/unit/java/android/net/IpSecAlgorithmTest.java
index 1482055..54ad961 100644
--- a/tests/unit/java/android/net/IpSecAlgorithmTest.java
+++ b/tests/unit/java/android/net/IpSecAlgorithmTest.java
@@ -27,6 +27,7 @@
 import android.content.res.Resources;
 import android.os.Build;
 import android.os.Parcel;
+import android.os.SystemProperties;
 
 import androidx.test.filters.SmallTest;
 
@@ -123,9 +124,7 @@
 
     @Test
     public void testValidationForAlgosAddedInS() throws Exception {
-        if (Build.VERSION.DEVICE_INITIAL_SDK_INT <= Build.VERSION_CODES.R) {
-            return;
-        }
+        if (SystemProperties.getInt("ro.vendor.api_level", 10000) <= Build.VERSION_CODES.R) return;
 
         for (int len : new int[] {160, 224, 288}) {
             checkCryptKeyLenValidation(IpSecAlgorithm.CRYPT_AES_CTR, len);
@@ -194,15 +193,17 @@
     }
 
     private static Set<String> getMandatoryAlgos() {
+        int vendorApiLevel = SystemProperties.getInt("ro.vendor.api_level", 10000);
         return CollectionUtils.filter(
                 ALGO_TO_REQUIRED_FIRST_SDK.keySet(),
-                i -> Build.VERSION.DEVICE_INITIAL_SDK_INT >= ALGO_TO_REQUIRED_FIRST_SDK.get(i));
+                i -> vendorApiLevel >= ALGO_TO_REQUIRED_FIRST_SDK.get(i));
     }
 
     private static Set<String> getOptionalAlgos() {
+        int vendorApiLevel = SystemProperties.getInt("ro.vendor.api_level", 10000);
         return CollectionUtils.filter(
                 ALGO_TO_REQUIRED_FIRST_SDK.keySet(),
-                i -> Build.VERSION.DEVICE_INITIAL_SDK_INT < ALGO_TO_REQUIRED_FIRST_SDK.get(i));
+                i -> vendorApiLevel < ALGO_TO_REQUIRED_FIRST_SDK.get(i));
     }
 
     @Test