diff --git a/src/process_wrap.cc b/src/process_wrap.cc
index 3dcde0962af080..8c8e4704be4f82 100644
--- a/src/process_wrap.cc
+++ b/src/process_wrap.cc
@@ -121,35 +121,29 @@ class ProcessWrap : public HandleWrap {
 
     // options.uid
     Local<Value> uid_v = js_options->Get(env->uid_string());
-    if (uid_v->IsInt32()) {
+    if (!uid_v->IsUndefined() && !uid_v->IsNull()) {
+      CHECK(uid_v->IsInt32());
       const int32_t uid = uid_v->Int32Value(env->context()).FromJust();
       options.flags |= UV_PROCESS_SETUID;
       options.uid = static_cast<uv_uid_t>(uid);
-    } else if (!uid_v->IsUndefined() && !uid_v->IsNull()) {
-      return env->ThrowTypeError("options.uid should be a number");
     }
 
     // options.gid
     Local<Value> gid_v = js_options->Get(env->gid_string());
-    if (gid_v->IsInt32()) {
+    if (!gid_v->IsUndefined() && !gid_v->IsNull()) {
+      CHECK(gid_v->IsInt32());
       const int32_t gid = gid_v->Int32Value(env->context()).FromJust();
       options.flags |= UV_PROCESS_SETGID;
       options.gid = static_cast<uv_gid_t>(gid);
-    } else if (!gid_v->IsUndefined() && !gid_v->IsNull()) {
-      return env->ThrowTypeError("options.gid should be a number");
     }
 
     // TODO(bnoordhuis) is this possible to do without mallocing ?
 
     // options.file
     Local<Value> file_v = js_options->Get(env->file_string());
-    node::Utf8Value file(env->isolate(),
-                         file_v->IsString() ? file_v : Local<Value>());
-    if (file.length() > 0) {
-      options.file = *file;
-    } else {
-      return env->ThrowTypeError("Bad argument");
-    }
+    CHECK(file_v->IsString());
+    node::Utf8Value file(env->isolate(), file_v);
+    options.file = *file;
 
     // options.args
     Local<Value> argv_v = js_options->Get(env->args_string());
diff --git a/src/spawn_sync.cc b/src/spawn_sync.cc
index 689f605e1446cd..68e78147578ff1 100644
--- a/src/spawn_sync.cc
+++ b/src/spawn_sync.cc
@@ -734,8 +734,7 @@ int SyncProcessRunner::ParseOptions(Local<Value> js_value) {
   }
   Local<Value> js_uid = js_options->Get(env()->uid_string());
   if (IsSet(js_uid)) {
-    if (!js_uid->IsInt32())
-      return UV_EINVAL;
+    CHECK(js_uid->IsInt32());
     const int32_t uid = js_uid->Int32Value(env()->context()).FromJust();
     uv_process_options_.uid = static_cast<uv_uid_t>(uid);
     uv_process_options_.flags |= UV_PROCESS_SETUID;
@@ -743,8 +742,7 @@ int SyncProcessRunner::ParseOptions(Local<Value> js_value) {
 
   Local<Value> js_gid = js_options->Get(env()->gid_string());
   if (IsSet(js_gid)) {
-    if (!js_gid->IsInt32())
-      return UV_EINVAL;
+    CHECK(js_gid->IsInt32());
     const int32_t gid = js_gid->Int32Value(env()->context()).FromJust();
     uv_process_options_.gid = static_cast<uv_gid_t>(gid);
     uv_process_options_.flags |= UV_PROCESS_SETGID;
@@ -760,28 +758,21 @@ int SyncProcessRunner::ParseOptions(Local<Value> js_value) {
 
   Local<Value> js_timeout = js_options->Get(env()->timeout_string());
   if (IsSet(js_timeout)) {
-    if (!js_timeout->IsNumber())
-      return UV_EINVAL;
+    CHECK(js_timeout->IsNumber());
     int64_t timeout = js_timeout->IntegerValue();
-    if (timeout < 0)
-      return UV_EINVAL;
     timeout_ = static_cast<uint64_t>(timeout);
   }
 
   Local<Value> js_max_buffer = js_options->Get(env()->max_buffer_string());
   if (IsSet(js_max_buffer)) {
-    if (!js_max_buffer->IsUint32())
-      return UV_EINVAL;
+    CHECK(js_max_buffer->IsUint32());
     max_buffer_ = js_max_buffer->Uint32Value();
   }
 
   Local<Value> js_kill_signal = js_options->Get(env()->kill_signal_string());
   if (IsSet(js_kill_signal)) {
-    if (!js_kill_signal->IsInt32())
-      return UV_EINVAL;
+    CHECK(js_kill_signal->IsInt32());
     kill_signal_ = js_kill_signal->Int32Value();
-    if (kill_signal_ == 0)
-      return UV_EINVAL;
   }
 
   Local<Value> js_stdio = js_options->Get(env()->stdio_string());