diff --git a/OneSignalSDK/onesignal/in-app-messages/src/main/java/com/onesignal/inAppMessages/internal/triggers/impl/DynamicTriggerController.kt b/OneSignalSDK/onesignal/in-app-messages/src/main/java/com/onesignal/inAppMessages/internal/triggers/impl/DynamicTriggerController.kt
index b7dd35afd7..a37aa6a402 100644
--- a/OneSignalSDK/onesignal/in-app-messages/src/main/java/com/onesignal/inAppMessages/internal/triggers/impl/DynamicTriggerController.kt
+++ b/OneSignalSDK/onesignal/in-app-messages/src/main/java/com/onesignal/inAppMessages/internal/triggers/impl/DynamicTriggerController.kt
@@ -75,10 +75,12 @@ internal class DynamicTriggerController(
                 return true
             }
 
-            val offset = requiredTimeInterval - currentTimeInterval
-            if (offset <= 0L) {
+            // Compare before subtracting: with an unbounded time since the last in-app
+            // message, a negative required interval would overflow the offset.
+            if (currentTimeInterval >= requiredTimeInterval) {
                 return false
             }
+            val offset = requiredTimeInterval - currentTimeInterval
 
             // Prevents re-scheduling timers for messages that we're already waiting on
             if (scheduledMessages.contains(triggerId)) {
@@ -149,8 +151,8 @@ internal class DynamicTriggerController(
     companion object {
         private const val REQUIRED_ACCURACY = 0.3
 
-        // Assume last time an In-App Message was displayed a very very long time ago.
-        private const val DEFAULT_LAST_IN_APP_TIME_AGO: Long = 999999
+        // If no In-App Message has been dismissed yet, treat the last one as infinitely long ago.
+        private const val DEFAULT_LAST_IN_APP_TIME_AGO: Long = Long.MAX_VALUE
     }
 
     override fun subscribe(handler: ITriggerHandler) = events.subscribe(handler)
diff --git a/OneSignalSDK/onesignal/in-app-messages/src/test/java/com/onesignal/inAppMessages/internal/triggers/impl/DynamicTriggerControllerTests.kt b/OneSignalSDK/onesignal/in-app-messages/src/test/java/com/onesignal/inAppMessages/internal/triggers/impl/DynamicTriggerControllerTests.kt
new file mode 100644
index 0000000000..5dee068eb2
--- /dev/null
+++ b/OneSignalSDK/onesignal/in-app-messages/src/test/java/com/onesignal/inAppMessages/internal/triggers/impl/DynamicTriggerControllerTests.kt
@@ -0,0 +1,64 @@
+package com.onesignal.inAppMessages.internal.triggers.impl
+
+import com.onesignal.inAppMessages.internal.Trigger
+import com.onesignal.inAppMessages.internal.state.InAppStateService
+import com.onesignal.mocks.MockHelper
+import com.onesignal.session.internal.session.ISessionService
+import io.kotest.core.spec.style.FunSpec
+import io.kotest.matchers.shouldBe
+import io.mockk.mockk
+import org.json.JSONObject
+
+private fun timeSinceLastInAppTrigger(
+    seconds: Number,
+    operator: Trigger.OSTriggerOperator = Trigger.OSTriggerOperator.GREATER_THAN
+): Trigger {
+    val json = JSONObject()
+    json.put("id", "trigger-id")
+    json.put("kind", Trigger.OSTriggerKind.TIME_SINCE_LAST_IN_APP.toString())
+    json.put("operator", operator.toString())
+    json.put("value", seconds)
+    return Trigger(json)
+}
+
+class DynamicTriggerControllerTests : FunSpec({
+    val oneHourInSeconds = 3600
+
+    test("time since last in-app trigger fires when no in-app message was dismissed yet") {
+        // Given
+        val state = InAppStateService()
+        val controller = DynamicTriggerController(state, mockk<ISessionService>(relaxed = true), MockHelper.time(1_000_000))
+
+        // When
+        val result = controller.dynamicTriggerShouldFire(timeSinceLastInAppTrigger(oneHourInSeconds))
+
+        // Then
+        result shouldBe true
+    }
+
+    test("time since last in-app trigger does not fire before the interval has elapsed") {
+        // Given
+        val now = 10_000_000L
+        val state = InAppStateService()
+        state.lastTimeInAppDismissed = now - 60_000L
+        val controller = DynamicTriggerController(state, mockk<ISessionService>(relaxed = true), MockHelper.time(now))
+
+        // When
+        val result = controller.dynamicTriggerShouldFire(timeSinceLastInAppTrigger(oneHourInSeconds))
+
+        // Then
+        result shouldBe false
+    }
+
+    test("time since last in-app trigger with a negative less-than value does not fire when no in-app message was dismissed yet") {
+        // Given
+        val state = InAppStateService()
+        val controller = DynamicTriggerController(state, mockk<ISessionService>(relaxed = true), MockHelper.time(1_000_000))
+
+        // When
+        val result = controller.dynamicTriggerShouldFire(timeSinceLastInAppTrigger(-1, Trigger.OSTriggerOperator.LESS_THAN))
+
+        // Then
+        result shouldBe false
+    }
+})