diff --git a/src/main/scala/system/Generator.scala b/src/main/scala/system/Generator.scala
index c5862c37..50597e11 100644
--- a/src/main/scala/system/Generator.scala
+++ b/src/main/scala/system/Generator.scala
@@ -47,41 +47,43 @@ object Generator extends GeneratorApp {
       "rv32mi-p-sbreak",
       "rv32ui-p-sll")
 
+
   override def addTestSuites {
     import DefaultTestSuites._
     val xlen = params(XLen)
     // TODO: for now only generate tests for the first core in the first subsystem
-    val tileParams = params(RocketTilesKey).head
-    val coreParams = tileParams.core
-    val vm = coreParams.useVM
-    val env = if (vm) List("p","v") else List("p")
-    coreParams.fpu foreach { case cfg =>
-      if (xlen == 32) {
-        TestGeneration.addSuites(env.map(rv32uf))
-        if (cfg.fLen >= 64)
-          TestGeneration.addSuites(env.map(rv32ud))
-      } else {
-        TestGeneration.addSuite(rv32udBenchmarks)
-        TestGeneration.addSuites(env.map(rv64uf))
-        if (cfg.fLen >= 64)
-          TestGeneration.addSuites(env.map(rv64ud))
+    params(RocketTilesKey).headOption.map { tileParams =>
+      val coreParams = tileParams.core
+      val vm = coreParams.useVM
+      val env = if (vm) List("p","v") else List("p")
+      coreParams.fpu foreach { case cfg =>
+        if (xlen == 32) {
+          TestGeneration.addSuites(env.map(rv32uf))
+          if (cfg.fLen >= 64)
+            TestGeneration.addSuites(env.map(rv32ud))
+        } else {
+          TestGeneration.addSuite(rv32udBenchmarks)
+          TestGeneration.addSuites(env.map(rv64uf))
+          if (cfg.fLen >= 64)
+            TestGeneration.addSuites(env.map(rv64ud))
+        }
       }
-    }
-    if (coreParams.useAtomics) {
-      if (tileParams.dcache.flatMap(_.scratch).isEmpty)
-        TestGeneration.addSuites(env.map(if (xlen == 64) rv64ua else rv32ua))
-      else
-        TestGeneration.addSuites(env.map(if (xlen == 64) rv64uaSansLRSC else rv32uaSansLRSC))
-    }
-    if (coreParams.useCompressed) TestGeneration.addSuites(env.map(if (xlen == 64) rv64uc else rv32uc))
-    val (rvi, rvu) =
-      if (xlen == 64) ((if (vm) rv64i else rv64pi), rv64u)
-      else            ((if (vm) rv32i else rv32pi), rv32u)
+      if (coreParams.useAtomics) {
+        if (tileParams.dcache.flatMap(_.scratch).isEmpty)
+          TestGeneration.addSuites(env.map(if (xlen == 64) rv64ua else rv32ua))
+        else
+          TestGeneration.addSuites(env.map(if (xlen == 64) rv64uaSansLRSC else rv32uaSansLRSC))
+      }
+      if (coreParams.useCompressed) TestGeneration.addSuites(env.map(if (xlen == 64) rv64uc else rv32uc))
+      val (rvi, rvu) =
+        if (xlen == 64) ((if (vm) rv64i else rv64pi), rv64u)
+        else            ((if (vm) rv32i else rv32pi), rv32u)
 
-    TestGeneration.addSuites(rvi.map(_("p")))
-    TestGeneration.addSuites((if (vm) List("v") else List()).flatMap(env => rvu.map(_(env))))
-    TestGeneration.addSuite(benchmarks)
-    TestGeneration.addSuite(new RegressionTestSuite(if (xlen == 64) rv64RegrTestNames else rv32RegrTestNames))
+      TestGeneration.addSuites(rvi.map(_("p")))
+      TestGeneration.addSuites((if (vm) List("v") else List()).flatMap(env => rvu.map(_(env))))
+      TestGeneration.addSuite(benchmarks)
+      TestGeneration.addSuite(new RegressionTestSuite(if (xlen == 64) rv64RegrTestNames else rv32RegrTestNames))
+    }
   }
 
   val longName = names.configProject + "." + names.configs