diff --git a/src/config/mod.rs b/src/config/mod.rs
index bd178ce..ab79c75 100644
--- a/src/config/mod.rs
+++ b/src/config/mod.rs
@@ -187,6 +187,8 @@ impl ConfigSet {
                     return Err(ConfigLoadError::NameDuplicate(path.to_owned()));
                 }
 
+                // TODO: check if it contains at least a filter, and warn the user about the problem
+
                 name_set.insert(config.name.clone());
                 specific.push(config);
             }
@@ -479,26 +481,36 @@ mod tests {
         assert_eq!(config_set.unwrap_err(), ConfigLoadError::MissingName(specific_path_copy))
     }
 
-    #[test]
-    fn test_config_set_specific_file_duplicate_name() {
+    pub fn create_temp_espanso_directory() -> TempDir {
         let tmp_dir = TempDir::new().expect("unable to create temp directory");
         let default_path = tmp_dir.path().join(DEFAULT_CONFIG_FILE_NAME);
         fs::write(default_path, DEFAULT_CONFIG_FILE_CONTENT);
 
-        let specific_path = tmp_dir.path().join("specific.yaml");
+        tmp_dir
+    }
+
+    pub fn create_temp_file_in_dir(tmp_dir: &TempDir, name: &str, content: &str) -> PathBuf {
+        let specific_path = tmp_dir.path().join(name);
         let specific_path_copy = specific_path.clone();
-        fs::write(specific_path, r###"
+        fs::write(specific_path, content);
+
+        specific_path_copy
+    }
+
+    #[test]
+    fn test_config_set_specific_file_duplicate_name() {
+        let tmp_dir = create_temp_espanso_directory();
+
+        let specific_path = create_temp_file_in_dir(&tmp_dir, "specific.yaml", r###"
         name: specific1
         "###);
 
-        let specific_path2 = tmp_dir.path().join("specific2.yaml");
-        let specific_path_copy2 = specific_path2.clone();
-        fs::write(specific_path2, r###"
+        let specific_path2 = create_temp_file_in_dir(&tmp_dir, "specific2.yaml", r###"
         name: specific1
         "###);
 
         let config_set = ConfigSet::load(tmp_dir.path());
         assert!(config_set.is_err());
-        assert_eq!(config_set.unwrap_err(), ConfigLoadError::NameDuplicate(specific_path_copy2))
+        assert_eq!(config_set.unwrap_err(), ConfigLoadError::NameDuplicate(specific_path2))
     }
 }
\ No newline at end of file
diff --git a/src/config/runtime.rs b/src/config/runtime.rs
index fefef36..b1928d1 100644
--- a/src/config/runtime.rs
+++ b/src/config/runtime.rs
@@ -176,4 +176,122 @@ impl <'a, S: SystemManager> super::ConfigManager<'a> for RuntimeConfigManager<'a
     fn matches(&'a self) -> &'a Vec<Match> {
         &self.active_config().matches
     }
+}
+
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::io::Write;
+    use tempfile::{NamedTempFile, TempDir};
+    use crate::config::{DEFAULT_CONFIG_FILE_NAME, DEFAULT_CONFIG_FILE_CONTENT};
+    use std::fs;
+    use std::path::PathBuf;
+    use crate::config::tests::{create_temp_espanso_directory, create_temp_file_in_dir};
+
+    struct DummySystemManager {}
+    impl SystemManager for DummySystemManager {
+        fn get_current_window_title(&self) -> Option<String> {
+            Some("title".to_owned())
+        }
+        fn get_current_window_class(&self) -> Option<String> {
+            Some("class".to_owned())
+        }
+        fn get_current_window_executable(&self) -> Option<String> {
+            Some("exec".to_owned())
+        }
+    }
+    impl DummySystemManager {
+        pub fn new() -> DummySystemManager {
+            DummySystemManager{}
+        }
+    }
+
+    #[test]
+    fn test_runtime_constructor_regex_load_correctly() {
+        let tmp_dir = create_temp_espanso_directory();
+
+        let specific_path = create_temp_file_in_dir(&tmp_dir, "specific.yaml", r###"
+        name: myname1
+        filter_exec: "Title"
+        "###);
+
+        let specific_path2 = create_temp_file_in_dir(&tmp_dir, "specific2.yaml", r###"
+        name: myname2
+        filter_title: "Yeah"
+        filter_class: "Car"
+        "###);
+
+        let specific_path3 = create_temp_file_in_dir(&tmp_dir, "specific3.yaml", r###"
+        name: myname3
+        filter_title: "Nice"
+        "###);
+
+        let config_set = ConfigSet::load(tmp_dir.path());
+        assert!(config_set.is_ok());
+
+        let dummy_system_manager = DummySystemManager::new();
+
+        let config_manager = RuntimeConfigManager::new(config_set.unwrap(), dummy_system_manager);
+
+        assert_eq!(config_manager.exec_regexps.len(), 3);
+        assert_eq!(config_manager.title_regexps.len(), 3);
+        assert_eq!(config_manager.class_regexps.len(), 3);
+
+        assert!(config_manager.class_regexps[0].is_none());
+        assert!(config_manager.class_regexps[1].is_some());
+        assert!(config_manager.class_regexps[2].is_none());
+
+        assert!(config_manager.title_regexps[0].is_none());
+        assert!(config_manager.title_regexps[1].is_some());
+        assert!(config_manager.title_regexps[2].is_some());
+
+        assert!(config_manager.exec_regexps[0].is_some());
+        assert!(config_manager.exec_regexps[1].is_none());
+        assert!(config_manager.exec_regexps[2].is_none());
+    }
+
+    #[test]
+    fn test_runtime_constructor_malformed_regexes_are_ignored() {
+        let tmp_dir = create_temp_espanso_directory();
+
+        let specific_path = create_temp_file_in_dir(&tmp_dir, "specific.yaml", r###"
+        name: myname1
+        filter_exec: "[`-_]"
+        "###);
+
+        let specific_path2 = create_temp_file_in_dir(&tmp_dir, "specific2.yaml", r###"
+        name: myname2
+        filter_title: "[`-_]"
+        filter_class: "Car"
+        "###);
+
+        let specific_path3 = create_temp_file_in_dir(&tmp_dir, "specific3.yaml", r###"
+        name: myname3
+        filter_title: "Nice"
+        "###);
+
+        let config_set = ConfigSet::load(tmp_dir.path());
+        assert!(config_set.is_ok());
+
+        let dummy_system_manager = DummySystemManager::new();
+
+        let config_manager = RuntimeConfigManager::new(config_set.unwrap(), dummy_system_manager);
+
+        assert_eq!(config_manager.exec_regexps.len(), 3);
+        assert_eq!(config_manager.title_regexps.len(), 3);
+        assert_eq!(config_manager.class_regexps.len(), 3);
+
+        assert!(config_manager.class_regexps[0].is_none());
+        assert!(config_manager.class_regexps[1].is_some());
+        assert!(config_manager.class_regexps[2].is_none());
+
+        assert!(config_manager.title_regexps[0].is_none());
+        assert!(config_manager.title_regexps[1].is_none());
+        assert!(config_manager.title_regexps[2].is_some());
+
+        assert!(config_manager.exec_regexps[0].is_none());
+        assert!(config_manager.exec_regexps[1].is_none());
+        assert!(config_manager.exec_regexps[2].is_none());
+    }
 }
\ No newline at end of file