diff --git a/test_runner/src/main/kotlin/ftl/args/CreateCommonArgs.kt b/test_runner/src/main/kotlin/ftl/args/CreateCommonArgs.kt
index 773790796c..44b19a6d7e 100644
--- a/test_runner/src/main/kotlin/ftl/args/CreateCommonArgs.kt
+++ b/test_runner/src/main/kotlin/ftl/args/CreateCommonArgs.kt
@@ -26,7 +26,7 @@ fun CommonConfig.createCommonArgs(
     clientDetails = gcloud.clientDetails,
 
     // flank
-    maxTestShards = flank.maxTestShards!!,
+    maxTestShards = convertToShardCount(flank.maxTestShards!!),
     shardTime = flank.shardTime!!,
     repeatTests = flank.repeatTests!!,
     smartFlankGcsPath = flank.smartFlankGcsPath!!,
@@ -58,3 +58,8 @@ private val CommonConfig.defaultOutputStyle
 private val CommonConfig.hasMultipleExecutions
     get() = gcloud.flakyTestAttempts!! > 0 ||
             (!flank.disableSharding!! && flank.maxTestShards!! > 0)
+
+fun convertToShardCount(inputValue: Int): Int =
+    if (inputValue != -1)
+        inputValue else
+        IArgs.AVAILABLE_SHARD_COUNT_RANGE.last
diff --git a/test_runner/src/main/kotlin/ftl/args/IArgs.kt b/test_runner/src/main/kotlin/ftl/args/IArgs.kt
index 0aaff382b8..1821994b88 100644
--- a/test_runner/src/main/kotlin/ftl/args/IArgs.kt
+++ b/test_runner/src/main/kotlin/ftl/args/IArgs.kt
@@ -53,12 +53,6 @@ interface IArgs {
 
     fun useLocalResultDir() = localResultDir != defaultLocalResultsDir
 
-    fun convertToShardCount(inputValue: Int): Int = if (inputValue == -1) {
-        AVAILABLE_SHARD_COUNT_RANGE.last
-    } else {
-        inputValue
-    }
-
     companion object {
         // num_shards must be >= 1, and <= 50
         val AVAILABLE_SHARD_COUNT_RANGE = 1..50