diff --git a/src/app.rs b/src/app.rs
index 112548c6..0e61cc7d 100644
--- a/src/app.rs
+++ b/src/app.rs
@@ -1,5 +1,6 @@
 use std::collections::HashSet;
 use std::env;
+use std::path::Path;
 
 use atty::{self, Stream};
 
@@ -102,6 +103,10 @@ impl App {
             AppSettings::ColorNever
         };
 
+        // Check if the current directory contains a file name cache, if it does
+        // do not make the arguements for subcommand 'cache' required.
+        let arg_group_required = !Path::new("cache").exists();
+
         ClapApp::new(crate_name!())
             .version(crate_version!())
             .global_setting(clap_color_setting)
@@ -303,7 +308,7 @@ impl App {
                     ).group(
                         ArgGroup::with_name("cache-actions")
                             .args(&["init", "clear", "config-dir"])
-                            .required(true),
+                            .required(arg_group_required),
                     ).arg(
                         Arg::with_name("source")
                             .long("source")
diff --git a/src/main.rs b/src/main.rs
index 1c56d757..ff87f9b8 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -87,7 +87,8 @@ fn run_cache_subcommand(matches: &clap::ArgMatches) -> Result<()> {
     Ok(())
 }
 
-pub fn list_languages(assets: &HighlightingAssets, config: &Config) -> Result<()> {
+pub fn list_languages(config: &Config) -> Result<()> {
+    let assets = HighlightingAssets::new();
     let mut languages = assets
         .syntax_set
         .syntaxes()
@@ -143,7 +144,8 @@ pub fn list_languages(assets: &HighlightingAssets, config: &Config) -> Result<()
     Ok(())
 }
 
-pub fn list_themes(assets: &HighlightingAssets, cfg: &Config) -> Result<()> {
+pub fn list_themes(cfg: &Config) -> Result<()> {
+    let assets = HighlightingAssets::new();
     let themes = &assets.theme_set.themes;
     let mut config = cfg.clone();
     let mut style = HashSet::new();
@@ -174,6 +176,12 @@ pub fn list_themes(assets: &HighlightingAssets, cfg: &Config) -> Result<()> {
     Ok(())
 }
 
+fn run_controller(config: &Config) -> Result<bool> {
+    let assets = HighlightingAssets::new();
+    let controller = Controller::new(&config, &assets);
+    controller.run()
+}
+
 /// Returns `Err(..)` upon fatal errors. Otherwise, returns `Some(true)` on full success and
 /// `Some(false)` if any intermediate errors occurred (were printed).
 fn run() -> Result<bool> {
@@ -181,24 +189,32 @@ fn run() -> Result<bool> {
 
     match app.matches.subcommand() {
         ("cache", Some(cache_matches)) => {
-            run_cache_subcommand(cache_matches)?;
-            Ok(true)
+            // If there is a file named 'cache' in the current working directory,
+            // arguments for subcommand 'cache' are not mandatory.
+            // If there are non-zero arguments, execute the subcommand cache, else, open the file cache.
+            if !cache_matches.args.is_empty() {
+                run_cache_subcommand(cache_matches)?;
+                Ok(true)
+            } else {
+                let mut config = app.config()?;
+                config.files = vec![InputFile::Ordinary(&"cache")];
+
+                run_controller(&config)
+            }
         }
         _ => {
             let config = app.config()?;
-            let assets = HighlightingAssets::new();
 
             if app.matches.is_present("list-languages") {
-                list_languages(&assets, &config)?;
+                list_languages(&config)?;
 
                 Ok(true)
             } else if app.matches.is_present("list-themes") {
-                list_themes(&assets, &config)?;
+                list_themes(&config)?;
 
                 Ok(true)
             } else {
-                let controller = Controller::new(&config, &assets);
-                controller.run()
+                run_controller(&config)
             }
         }
     }