diff --git a/libguac/include/client.h b/libguac/include/client.h
index 35335985..8d87d092 100644
--- a/libguac/include/client.h
+++ b/libguac/include/client.h
@@ -296,8 +296,11 @@ guac_client* guac_get_client(int client_fd);
  * Enter the main network message handling loop for the given client.
  *
  * @param client The proxy client to start handling messages of/for.
+ * @return Zero if the client successfully started, non-zero if an error
+ *         occurs during startup. Note that this function will still return
+ *         zero if an error occurs while the client is running.
  */
-void guac_start_client(guac_client* client);
+int guac_start_client(guac_client* client);
 
 /**
  * Free all resources associated with the given client.
diff --git a/libguac/src/client.c b/libguac/src/client.c
index 276c7f83..cff714bc 100644
--- a/libguac/src/client.c
+++ b/libguac/src/client.c
@@ -387,18 +387,16 @@ void* __guac_client_input_thread(void* data) {
 
 }
 
-void guac_start_client(guac_client* client) {
+int guac_start_client(guac_client* client) {
 
     pthread_t input_thread, output_thread;
 
     if (pthread_create(&output_thread, NULL, __guac_client_output_thread, (void*) client)) {
-        /* THIS FUNCTION SHOULD RETURN A VALUE! */
-        return;
+        return -1;
     }
 
     if (pthread_create(&input_thread, NULL, __guac_client_input_thread, (void*) client)) {
-        /* THIS FUNCTION SHOULD RETURN A VALUE! */
-        return;
+        return -1;
     }
 
     /* Wait for I/O threads */
@@ -406,6 +404,7 @@ void guac_start_client(guac_client* client) {
     pthread_join(output_thread, NULL);
 
     /* Done */
+    return 0;
 
 }