diff --git a/faststreams.nimble b/faststreams.nimble
index 2554214..8baeea8 100644
--- a/faststreams.nimble
+++ b/faststreams.nimble
@@ -29,6 +29,9 @@ proc test(args, path: string) =
   #  " -d:asyncBackend=asyncdispatch " & common_args & " " & path
 
 task test, "Run all tests":
+  test "-d:debug   --threads:off", "tests/all_tests"
+  test "-d:release --threads:off", "tests/all_tests"
+  test "-d:danger  --threads:off", "tests/all_tests"
   test "-d:debug   --threads:on", "tests/all_tests"
   test "-d:release --threads:on", "tests/all_tests"
   test "-d:danger  --threads:on", "tests/all_tests"
diff --git a/tests/test_outputs.nim b/tests/test_outputs.nim
index 487bbe1..7c1003b 100644
--- a/tests/test_outputs.nim
+++ b/tests/test_outputs.nim
@@ -400,3 +400,28 @@ suite "randomized tests":
       if fileExists(randomBytesFileName):
         removeFile randomBytesFileName
 
+  test "ensureRunway":
+    var output = memoryOutput()
+
+    const writes = 256
+    var buffer = newSeq[byte](writes)
+    let totalBytes = block:
+      var tmp = 0
+      for i in 0..<writes:
+        tmp += i
+        buffer[i] = byte(i)
+      tmp
+
+    output.ensureRunway(totalBytes)
+
+    for i in 0..<writes:
+      output.write(buffer.toOpenArray(0, i - 1))
+
+    output.flush()
+
+    let res = output.getOutput()
+    var j = 0
+    for i in 0..<writes:
+      check:
+        res[j..<j+i] == buffer[0..<i]
+      j += i