diff --git a/src/lib.rs b/src/lib.rs
index ee75c56..5ff0528 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -17,7 +17,10 @@ fn concert_replacement(original: &str, replacement: &str) -> String {
 pub fn replace(search: &String, replace: String, input: String) -> String {
     let mut index = 0;
     let mut output = input;
-    let search_pattern = Regex::new(&format!("(?i){search}")).unwrap();
+    let search_pattern = match Regex::new(&format!("(?i){search}")) {
+        Ok(pattern) => pattern,
+        Err(_) => return output,
+    };
 
     while let Some(search_match) = search_pattern.find_at(&output, index) {
         let start = search_match.start();
diff --git a/tests/features/regex.feature b/tests/features/regex.feature
index 0e07ec5..3e3ad5c 100644
--- a/tests/features/regex.feature
+++ b/tests/features/regex.feature
@@ -17,3 +17,9 @@ Feature: Regex search and replace
     And Replace is 'Hello ${1}s'
     And Input is 'Hello world'
     Then Output is 'Hello worlds'
+
+  Scenario: You can search with an invalid regular expression
+    Given Search is '(\w+'
+    And Replace is 'new'
+    And Input is 'this is a'
+    Then Output is 'this is a'