diff --git a/benchmarks/wasm/return.wat b/benchmarks/wasm/return.wat
index f9609173..5bf59d17 100644
--- a/benchmarks/wasm/return.wat
+++ b/benchmarks/wasm/return.wat
@@ -1,13 +1,16 @@
 (module
   (type (;0;) (func))
-  (func (;0;) (type 0)
-    block ;; label = @1
+  (type (;1;) (func (result i32)))
+  (func (type 1)
+    block
+      i32.const 42
       return
     end
-    unreachable
+    i32.const 100
   )
-  (func (;1;) (type 0)
+  (func (type 0)
     call 0
+    unreachable
   )
   (start 1)
-)
\ No newline at end of file
+)
diff --git a/benchmarks/wasm/tribonacci.wat b/benchmarks/wasm/tribonacci.wat
new file mode 100644
index 00000000..01a50848
--- /dev/null
+++ b/benchmarks/wasm/tribonacci.wat
@@ -0,0 +1,43 @@
+(module
+  (type (;0;) (func (param i32) (result i32)))
+  (type (;1;) (func (result i32)))
+  (func (;0;) (type 0) (param i32) (result i32)
+    local.get 0
+    if (result i32)  ;; label = @1
+      local.get 0
+      i32.const 1
+      i32.eq
+      if (result i32)  ;; label = @2
+        i32.const 1
+      else
+        local.get 0
+        i32.const 2
+        i32.eq
+        if (result i32)  ;; label = @3
+          i32.const 1
+        else
+          local.get 0
+          i32.const 1
+          i32.sub
+          call 0
+          local.get 0
+          i32.const 2
+          i32.sub
+          call 0
+          i32.add
+          local.get 0
+          i32.const 3
+          i32.sub
+          call 0
+          i32.add
+        end
+      end
+    else
+      i32.const 0
+    end)
+  (func (;1;) (type 1) (result i32)
+    i32.const 12
+    call 0)
+  (start 1)
+  (memory (;0;) 0)
+  (export "memory" (memory 0)))
diff --git a/benchmarks/wasm/tribonacci_ret.rs b/benchmarks/wasm/tribonacci_ret.rs
new file mode 100644
index 00000000..ae576056
--- /dev/null
+++ b/benchmarks/wasm/tribonacci_ret.rs
@@ -0,0 +1,13 @@
+#[no_mangle]
+#[inline(never)]
+fn tribonacci(n: i32) -> i32 {
+    if n == 0 { 0 }
+    else if n == 1 { 1 }
+    else if n == 2 { 1 }
+    else { tribonacci(n - 1) + tribonacci(n - 2) + tribonacci(n - 3) }
+}
+
+#[no_mangle]
+fn real_main() -> i32 {
+    tribonacci(12)
+}
diff --git a/benchmarks/wasm/tribonacci_ret.wat b/benchmarks/wasm/tribonacci_ret.wat
new file mode 100644
index 00000000..88e70e23
--- /dev/null
+++ b/benchmarks/wasm/tribonacci_ret.wat
@@ -0,0 +1,68 @@
+(module $tribonacci.wat.temp
+  (type (;0;) (func (param i32) (result i32)))
+  (type (;1;) (func (result i32)))
+  (func $tribonacci (type 0) (param i32) (result i32)
+    (local i32 i32)
+    local.get 0
+    i32.const 2
+    i32.shl
+    i32.const 1048576
+    i32.add
+    local.set 1
+    i32.const 0
+    local.set 2
+    local.get 0
+    local.set 0
+    loop (result i32)  ;; label = @1
+      local.get 2
+      local.set 2
+      local.get 1
+      local.set 1
+      block  ;; label = @2
+        local.get 0
+        local.tee 0
+        i32.const 2
+        i32.gt_u
+        br_if 0 (;@2;)
+        local.get 1
+        i32.load
+        local.get 2
+        i32.add
+        return
+      end
+      local.get 1
+      i32.const -12
+      i32.add
+      local.set 1
+      local.get 0
+      i32.const -1
+      i32.add
+      call $tribonacci
+      local.get 0
+      i32.const -2
+      i32.add
+      call $tribonacci
+      i32.add
+      local.get 2
+      i32.add
+      local.set 2
+      local.get 0
+      i32.const -3
+      i32.add
+      local.set 0
+      br 0 (;@1;)
+    end)
+  (func $real_main (type 1) (result i32)
+    i32.const 12
+    call $tribonacci)
+  (table (;0;) 1 1 funcref)
+  (memory (;0;) 17)
+  (global $__stack_pointer (mut i32) (i32.const 1048576))
+  (global (;1;) i32 (i32.const 1048588))
+  (global (;2;) i32 (i32.const 1048592))
+  (export "memory" (memory 0))
+  (export "tribonacci" (func $tribonacci))
+  (export "real_main" (func $real_main))
+  (export "__data_end" (global 1))
+  (export "__heap_base" (global 2))
+  (data $.rodata (i32.const 1048576) "\00\00\00\00\01\00\00\00\01\00\00\00"))
diff --git a/src/main/scala/wasm/MiniWasm.scala b/src/main/scala/wasm/MiniWasm.scala
index b2789e2e..8efe0e12 100644
--- a/src/main/scala/wasm/MiniWasm.scala
+++ b/src/main/scala/wasm/MiniWasm.scala
@@ -7,6 +7,8 @@ import gensym.wasm.memory._
 import scala.collection.mutable.ArrayBuffer
 import scala.collection.mutable.HashMap
 
+case class Trap() extends Exception
+
 case class ModuleInstance(
     types: List[FuncType],
     funcs: HashMap[Int, WIR],
@@ -259,7 +261,7 @@ object Evaluator {
         eval(rest, I32V(value) :: newStack, frame, kont, trail, ret)
       case Nop =>
         eval(rest, stack, frame, kont, trail, ret)
-      case Unreachable => throw new RuntimeException("Unreachable")
+      case Unreachable => throw Trap()
       case Block(ty, inner) =>
         val k: Cont[Ans] = (retStack) =>
           eval(rest, retStack.take(ty.toList.size) ++ stack, frame, kont, trail, ret)
@@ -302,7 +304,7 @@ object Evaluator {
           eval(rest, retStack.take(ty.out.size) ++ newStack, frame, kont, trail, ret)
         // We push newK on the trail since function creates a new block to escape
         // (more or less like `return`)
-        eval(body, List(), newFrame, newK, newK :: trail, ret+1)
+        eval(body, List(), newFrame, newK, List(newK), 0)
       case Call(f) if frame.module.funcs(f).isInstanceOf[Import] =>
         frame.module.funcs(f) match {
           case Import("console", "log", _) =>
diff --git a/src/test/scala/genwasym/TestEval.scala b/src/test/scala/genwasym/TestEval.scala
index f2d66b15..1c808fad 100644
--- a/src/test/scala/genwasym/TestEval.scala
+++ b/src/test/scala/genwasym/TestEval.scala
@@ -14,8 +14,6 @@ import collection.mutable.ArrayBuffer
 import org.scalatest.FunSuite
 
 class TestEval extends FunSuite {
-
-  // Mostly testing the files generated form `benchmarks/wasm/test.rs`
   def testFile(filename: String,
                main: Option[String] = None,
                expected: Option[Int] = None) = {
@@ -40,10 +38,19 @@ class TestEval extends FunSuite {
   test("fact") { testFile("./benchmarks/wasm/fact.wat", None, Some(120)) }
   test("loop") { testFile("./benchmarks/wasm/loop.wat", None, Some(10)) }
   test("even-odd") { testFile("./benchmarks/wasm/even_odd.wat", None, Some(1)) }
-  test("return") { testFile("./benchmarks/wasm/return.wat", None, None) }
   test("load") { testFile("./benchmarks/wasm/load.wat", None, Some(1)) }
   test("btree") { testFile("./benchmarks/wasm/btree/2o1u-unlabeled.wat") }
   test("fib") { testFile("./benchmarks/wasm/fib.wat", None, Some(144)) }
+  test("tribonacci") { testFile("./benchmarks/wasm/tribonacci.wat", None, Some(504)) }
+
+  test("return") {
+    intercept[gensym.wasm.miniwasm.Trap] {
+      testFile("./benchmarks/wasm/return.wat", None, None)
+    }
+  }
+
+  // FIXME:
+  //test("tribonacci-ret") { testFile("./benchmarks/wasm/tribonacci_ret.wat", None, Some(504)) }
 
   // TODO: add wasm spec tests? How to utilize wast files?
 }