diff --git a/src/http/http.cc b/src/http/http.cc
index 4fcb08fcd36..5fb44ebf9db 100644
--- a/src/http/http.cc
+++ b/src/http/http.cc
@@ -21,20 +21,21 @@ http_req_t::resource_t::resource_t(const http_req_t::resource_t &from, const htt
 }
 
 http_req_t::resource_t::resource_t(const std::string &_val) {
-    assign(_val);
+    if (!assign(_val)) throw std::invalid_argument(_val);
 }
 
 http_req_t::resource_t::resource_t(const char * _val, size_t size) {
-    assign(_val, size);
+    if (!assign(_val, size)) throw std::invalid_argument(_val);
 }
 
-void http_req_t::resource_t::assign(const std::string &_val) {
-    assign(_val.data(), _val.length());
+// Returns false if the assignment fails.
+MUST_USE bool http_req_t::resource_t::assign(const std::string &_val) {
+    return assign(_val.data(), _val.length());
 }
 
-void http_req_t::resource_t::assign(const char * _val, size_t size) {
-    // TODO: Do we actually prevent clients from getting a bad resource path up to here?
-    guarantee(size > 0 && _val[0] == resource_parts_sep_char[0], "resource path must start with a '/'");
+// Returns false if the assignment fails.
+MUST_USE bool http_req_t::resource_t::assign(const char * _val, size_t size) {
+    if (!(size > 0 && _val[0] == resource_parts_sep_char[0])) return false;
     val.reset(new char[size]);
     memcpy(val.get(), _val, size);
     val_size = size;
@@ -43,6 +44,7 @@ void http_req_t::resource_t::assign(const char * _val, size_t size) {
     tokenizer t(val.get() + 1, val.get() + size, resource_parts_sep);
     b = t.begin();
     e = t.end();
+    return true;
 }
 
 http_req_t::resource_t::iterator http_req_t::resource_t::begin() const {
@@ -176,6 +178,7 @@ http_res_t http_error_res(const std::string &content, http_status_code_t rescode
     return http_res_t(rescode, "application/text", content);
 }
 
+//TODO: What the hell is this?
 void test_header_parser() {
     http_req_t res("/foo/bar");
     //str_http_msg_parser_t http_msg_parser;
@@ -366,7 +369,7 @@ bool tcp_http_msg_parser_t::parse(tcp_conn_t *conn, http_req_t *req, signal_t *c
         return false;
     }
 
-    req->resource.assign(resource_string.resource);
+    if (!req->resource.assign(resource_string.resource)) return false;
     req->query_params = resource_string.query_params;
 
     std::string version_str = parser.readLine(closer);
diff --git a/src/http/http.hpp b/src/http/http.hpp
index de8b3b0dbbb..91b603fbf89 100644
--- a/src/http/http.hpp
+++ b/src/http/http.hpp
@@ -3,6 +3,7 @@
 #define HTTP_HTTP_HPP_
 
 #include <string>
+#include <stdexcept>
 #include <vector>
 
 #include "errors.hpp"
@@ -47,8 +48,8 @@ struct http_req_t {
         explicit resource_t(const std::string &_val);
         resource_t(const char* _val, size_t size);
 
-        void assign(const std::string &_val);
-        void assign(const char* _val, size_t size);
+        MUST_USE bool assign(const std::string &_val);
+        MUST_USE bool assign(const char* _val, size_t size);
         iterator begin() const;
         iterator end() const;
         std::string as_string(const iterator &from) const;