diff --git a/include/glaze/net/http_router.hpp b/include/glaze/net/http_router.hpp
index ecd9c75978..0f244dfd8b 100644
--- a/include/glaze/net/http_router.hpp
+++ b/include/glaze/net/http_router.hpp
@@ -299,6 +299,7 @@ namespace glz
        */
       void add(http_method method, std::string_view path, H handle, const route_spec& spec = {})
       {
+#if __cpp_exceptions
          try {
             // Install in the radix tree first. add_route can throw on conflict
             // (duplicate :param or *wildcard names at the same position); if it
@@ -316,6 +317,16 @@ namespace glz
             std::fprintf(stderr, "Error adding route '%.*s': %s\n", static_cast<int>(path.length()), path.data(),
                          e.what());
          }
+#else
+         // Under -fno-exceptions add_route's misuse-detection throws are
+         // compiled to fprintf+abort (see the matching #else branches below),
+         // so we cannot observe the conflict here and simply propagate the
+         // install. Misconfigured routes still get reported on stderr.
+         add_route(method, path, handle, spec.constraints);
+         auto& entry = routes[std::string(path)][method];
+         entry.handle = std::move(handle);
+         entry.spec = spec;
+#endif
       }
 
       /**
@@ -392,8 +403,14 @@ namespace glz
                   current->parameter_child->full_path = current->full_path + "/" + segment;
                }
                else if (current->parameter_child->parameter_name != param_name) {
-                  throw std::runtime_error("Route conflict: different parameter names at same position: :" +
-                                           current->parameter_child->parameter_name + " vs :" + param_name);
+                  const auto msg = "Route conflict: different parameter names at same position: :" +
+                                   current->parameter_child->parameter_name + " vs :" + param_name;
+#if __cpp_exceptions
+                  throw std::runtime_error(msg);
+#else
+                  std::fprintf(stderr, "%s\n", msg.c_str());
+                  std::abort();
+#endif
                }
 
                current = current->parameter_child.get();
@@ -402,7 +419,13 @@ namespace glz
                std::string wildcard_name = segment.substr(1);
 
                if (i != segments.size() - 1) {
-                  throw std::runtime_error("Wildcard must be the last segment in route: " + path_str);
+                  const auto msg = "Wildcard must be the last segment in route: " + path_str;
+#if __cpp_exceptions
+                  throw std::runtime_error(msg);
+#else
+                  std::fprintf(stderr, "%s\n", msg.c_str());
+                  std::abort();
+#endif
                }
 
                if (!current->wildcard_child) {
@@ -413,8 +436,14 @@ namespace glz
                   current->wildcard_child->full_path = current->full_path + "/" + segment;
                }
                else if (current->wildcard_child->parameter_name != wildcard_name) {
-                  throw std::runtime_error("Route conflict: different wildcard names at same position: *" +
-                                           current->wildcard_child->parameter_name + " vs *" + wildcard_name);
+                  const auto msg = "Route conflict: different wildcard names at same position: *" +
+                                   current->wildcard_child->parameter_name + " vs *" + wildcard_name;
+#if __cpp_exceptions
+                  throw std::runtime_error(msg);
+#else
+                  std::fprintf(stderr, "%s\n", msg.c_str());
+                  std::abort();
+#endif
                }
 
                current = current->wildcard_child.get();
diff --git a/include/glaze/rpc/registry.hpp b/include/glaze/rpc/registry.hpp
index c84f23c617..93b676fa76 100644
--- a/include/glaze/rpc/registry.hpp
+++ b/include/glaze/rpc/registry.hpp
@@ -328,6 +328,7 @@ namespace glz
                resp.reset(req_view);
                repe::state_view state{req_view, resp};
 
+#if __cpp_exceptions
                try {
                   it->second(state);
                }
@@ -335,6 +336,13 @@ namespace glz
                   resp.reset(req_view);
                   resp.set_error(error_code::parse_error, detail::build_registry_error(in.query, e.what()));
                }
+#else
+               // Builds with -fno-exceptions cannot catch handler-thrown
+               // exceptions; user code in `it->second` is expected to be
+               // exception-free, matching the rest of glaze's no-exceptions
+               // contract (see #2265).
+               it->second(state);
+#endif
             }
          }
          else {
@@ -412,6 +420,7 @@ namespace glz
          // Zero-copy call: state_view references the parsed request and response builder directly
          repe::state_view state{req, resp};
 
+#if __cpp_exceptions
          try {
             it->second(state);
          }
@@ -425,6 +434,10 @@ namespace glz
             resp.set_error(error_code::parse_error, "Unknown error");
             return;
          }
+#else
+         // -fno-exceptions: user handlers are expected to be exception-free (see #2265).
+         it->second(state);
+#endif
 
          // For notifications, response buffer stays empty (no response sent)
       }
@@ -529,6 +542,7 @@ namespace glz
          bool has_params = !req.params.str.empty() && req.params.str != "null";
          jsonrpc::state state{req.id, response, is_notification, has_params, req.params.str};
 
+#if __cpp_exceptions
          try {
             it->second(std::move(state));
          }
@@ -540,6 +554,10 @@ namespace glz
             return R"({"jsonrpc":"2.0","error":{"code":-32603,"message":"Internal error","data":)" +
                    write_json(std::string_view{e.what()}).value_or("null") + R"(},"id":)" + id_json + "}";
          }
+#else
+         // -fno-exceptions: user handlers are expected to be exception-free (see #2265).
+         it->second(std::move(state));
+#endif
 
          if (is_notification) {
             return std::nullopt;