diff --git a/OneSignalSDK/onesignal/core/src/main/java/com/onesignal/session/internal/outcomes/impl/OutcomeEventsRepository.kt b/OneSignalSDK/onesignal/core/src/main/java/com/onesignal/session/internal/outcomes/impl/OutcomeEventsRepository.kt
index c769f7d0ba..310824167b 100644
--- a/OneSignalSDK/onesignal/core/src/main/java/com/onesignal/session/internal/outcomes/impl/OutcomeEventsRepository.kt
+++ b/OneSignalSDK/onesignal/core/src/main/java/com/onesignal/session/internal/outcomes/impl/OutcomeEventsRepository.kt
@@ -8,6 +8,7 @@ import com.onesignal.session.internal.influence.Influence
 import com.onesignal.session.internal.influence.InfluenceChannel
 import com.onesignal.session.internal.influence.InfluenceType
 import com.onesignal.session.internal.influence.InfluenceType.Companion.fromString
+import com.onesignal.session.internal.outcomes.migrations.RemoveZeroSessionTimeRecords
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.withContext
 import org.json.JSONArray
@@ -101,6 +102,7 @@ internal class OutcomeEventsRepository(
     override suspend fun getAllEventsToSend(): List<OutcomeEventParams> {
         val events: MutableList<OutcomeEventParams> = ArrayList()
         withContext(Dispatchers.IO) {
+            RemoveZeroSessionTimeRecords.run(_databaseProvider)
             _databaseProvider.os.query(OutcomeEventsTable.TABLE_NAME) { cursor ->
                 if (cursor.moveToFirst()) {
                     do {
diff --git a/OneSignalSDK/onesignal/core/src/main/java/com/onesignal/session/internal/outcomes/migrations/RemoveZeroSessionTimeRecords.kt b/OneSignalSDK/onesignal/core/src/main/java/com/onesignal/session/internal/outcomes/migrations/RemoveZeroSessionTimeRecords.kt
new file mode 100644
index 0000000000..93bab4d4a3
--- /dev/null
+++ b/OneSignalSDK/onesignal/core/src/main/java/com/onesignal/session/internal/outcomes/migrations/RemoveZeroSessionTimeRecords.kt
@@ -0,0 +1,24 @@
+package com.onesignal.session.internal.outcomes.migrations
+
+import com.onesignal.core.internal.database.IDatabaseProvider
+import com.onesignal.session.internal.outcomes.impl.OutcomeEventsTable
+
+/**
+ * Purpose: Clean up invalid cached os__session_duration outcome records
+ * with zero session_time produced in SDK versions 5.1.15 to 5.1.20 so we stop
+ * sending these requests to the backend.
+ *
+ * Issue: SessionService.backgroundRun() didn't account for it being run more
+ * than one time in the background, when this happened it would create a
+ * outcome record with zero time which is invalid.
+ */
+object RemoveZeroSessionTimeRecords {
+    fun run(databaseProvider: IDatabaseProvider) {
+        databaseProvider.os.delete(
+            OutcomeEventsTable.TABLE_NAME,
+            OutcomeEventsTable.COLUMN_NAME_NAME + " = \"os__session_duration\"" +
+                " AND " + OutcomeEventsTable.COLUMN_NAME_SESSION_TIME + " = 0",
+            null,
+        )
+    }
+}