diff --git a/Collection.go b/Collection.go
index c7bdb89..45ea631 100644
--- a/Collection.go
+++ b/Collection.go
@@ -5,7 +5,6 @@ import (
 	"os"
 	"path/filepath"
 	"reflect"
-	"strings"
 	"sync"
 )
 
@@ -105,7 +104,7 @@ func (c *collection[T]) Clear() {
 
 // keyFile returns the file path for the given key.
 func (c *collection[T]) keyFile(key string) string {
-	return filepath.Join(c.directory, key+".json")
+	return filepath.Join(c.directory, key)
 }
 
 // loadFromDisk loads the collection data from the disk.
@@ -118,8 +117,8 @@ func (c *collection[T]) loadFromDisk() error {
 
 	files, err := file.Readdirnames(0)
 
-	for _, name := range files {
-		fileError := c.loadFileFromDisk(name)
+	for _, key := range files {
+		fileError := c.loadFileFromDisk(key)
 
 		if fileError != nil {
 			return fileError
@@ -134,8 +133,8 @@ func (c *collection[T]) loadFromDisk() error {
 }
 
 // loadFileFromDisk loads a single file from the disk.
-func (c *collection[T]) loadFileFromDisk(name string) error {
-	file, err := os.Open(filepath.Join(c.directory, name))
+func (c *collection[T]) loadFileFromDisk(key string) error {
+	file, err := os.Open(filepath.Join(c.directory, key))
 
 	if err != nil {
 		return err
@@ -146,10 +145,10 @@ func (c *collection[T]) loadFileFromDisk(name string) error {
 	err = decoder.Decode(value)
 
 	if err != nil {
+		file.Close()
 		return err
 	}
 
-	key := strings.TrimSuffix(name, filepath.Ext(name))
 	c.data.Store(key, value)
 	return file.Close()
 }
@@ -167,6 +166,7 @@ func (c *collection[T]) writeFileToDisk(key string, value *T) error {
 	err = encoder.Encode(value)
 
 	if err != nil {
+		file.Close()
 		return err
 	}
 
diff --git a/README.md b/README.md
index 986c40e..457557e 100644
--- a/README.md
+++ b/README.md
@@ -44,6 +44,8 @@ You can add as many directory hierarchies as you need but I recommend using a si
 
 ## Limitations
 
-This storage mechanism is suitable for small to medium data volume.
+* Keys cannot be empty and they cannot contain a directory separator like `/`.
 
-It is not suited for big data, however the package is pretty lightweight so you can combine it with a big data store.
+* This storage mechanism is only suitable for small to medium data volume.
+
+Ocean isn't meant to be used for big data, however the package is very lightweight so you can combine it with a big data store.