diff --git a/lib/android/src/main/kotlin/im/molly/monero/OwnedTxOut.kt b/lib/android/src/main/kotlin/im/molly/monero/OwnedTxOut.kt
index 41f86fd..d762e92 100644
--- a/lib/android/src/main/kotlin/im/molly/monero/OwnedTxOut.kt
+++ b/lib/android/src/main/kotlin/im/molly/monero/OwnedTxOut.kt
@@ -19,17 +19,17 @@ constructor(
     val spentInBlockHeight: Long,
 ) : Parcelable {
 
-    init {
-        require(blockHeight <= spentInBlockHeight)
-        require(amount >= 0) { "TX amount cannot be negative" }
-    }
-
     @IgnoredOnParcel
     val spent: Boolean = spentInBlockHeight != 0L
 
     @IgnoredOnParcel
     val notSpent = !spent
 
+    init {
+        require(notSpent || blockHeight <= spentInBlockHeight)
+        require(amount >= 0) { "TX amount $amount cannot be negative" }
+    }
+
     override fun equals(other: Any?): Boolean {
         if (this === other) return true
         if (javaClass != other?.javaClass) return false