diff --git a/src/h2load.cc b/src/h2load.cc
index 0c4121fe..df5e2a4c 100644
--- a/src/h2load.cc
+++ b/src/h2load.cc
@@ -1408,7 +1408,41 @@ int main(int argc, char **argv) {
   if (config.max_concurrent_streams == -1) {
     config.max_concurrent_streams = reqlines.size();
   }
+  
+  // if not in rate mode and -C is set, warn that we are ignoring it
+  if (!config.is_rate_mode() && config.nconns != 0) {
+    std::cerr << "-C: warning: This option can only be used with -r, and"
+              << " will be ignored otherwise." << std::endl;
+  }
 
+  ssize_t n_time = 0;
+  ssize_t c_time = 0; 
+  // only care about n_time and c_time in rate mode
+  if (config.is_rate_mode() && config.max_concurrent_streams != 0) {
+    n_time = (int)config.nreqs / 
+             ((int)config.rate * (int)config.max_concurrent_streams);
+    c_time = (int)config.nconns / (int)config.rate;
+  }
+  // check to see if the two ways of determining test time conflict
+  if (config.is_rate_mode() && (int)config.max_concurrent_streams != 0 &&
+      (n_time != c_time) && config.nreqs != 1 && config.nconns != 0) {
+    if ((int)config.nreqs < config.nconns) {
+      std::cerr << "-C, -n: warning: two different test times are being set. "
+                << std::endl;
+      std::cerr << "The test will run for "
+                << c_time
+                << " seconds." << std::endl;
+    }
+    else {
+      std::cout << "-C, -n: warning: two different test times are being set. "
+                << std::endl;
+      std::cout << "The smaller of the two will be chosen and the test will "
+                << "run for "
+                << std::min(n_time, c_time)
+                << " seconds." << std::endl;
+    }
+  }
+  
   Headers shared_nva;
   shared_nva.emplace_back(":scheme", config.scheme);
   if (config.port != config.default_port) {
diff --git a/src/h2load.h b/src/h2load.h
index a68b8dc5..986bf78c 100644
--- a/src/h2load.h
+++ b/src/h2load.h
@@ -57,6 +57,7 @@ using namespace nghttp2;
 namespace h2load {
 
 class Session;
+struct Worker;
 
 struct Config {
   std::vector<std::vector<nghttp2_nv>> nva;