diff --git a/src/modules/sway/window.cpp b/src/modules/sway/window.cpp
index 3b424c2f..04910394 100644
--- a/src/modules/sway/window.cpp
+++ b/src/modules/sway/window.cpp
@@ -141,9 +141,15 @@ std::string Window::rewriteTitle(const std::string& title)
 
   for (auto it = rules.begin(); it != rules.end(); ++it) {
     if (it.key().isString() && it->isString()) {
-      const std::regex rule{it.key().asString()};
-      if (std::regex_match(title, rule)) {
-        return std::regex_replace(title, rule, it->asString());
+      try {
+        // malformated regexes will cause an exception.
+        // in this case, log error and try the next rule.
+        const std::regex rule{it.key().asString()};
+        if (std::regex_match(title, rule)) {
+          return std::regex_replace(title, rule, it->asString());
+        }
+      } catch (const std::regex_error& e) {
+        spdlog::error("Invalid rule {}: {}", it.key().asString(), e.what());
       }
     }
   }