diff --git a/core/file.c b/core/file.c
index 19c5dd2e..ec9c02e1 100644
--- a/core/file.c
+++ b/core/file.c
@@ -104,7 +104,7 @@ void file_init(struct file *file, const gchar *name, unsigned int min)
 	file->f_name = name;
 }
 
-void cache_file_init(struct cache_file *file, gchar *subdir, gchar *name)
+void cache_file_init(struct cache_file *file, const gchar *subdir, const gchar *name)
 {
 	file->cf_file   = NULL;
 	file->cf_name   = name;
diff --git a/include/core/file.h b/include/core/file.h
index 5c3c50eb..bb78b405 100644
--- a/include/core/file.h
+++ b/include/core/file.h
@@ -55,14 +55,14 @@ struct file {
 
 
 struct cache_file {
-	FILE	*cf_file;   /* The cache file's IO stream.    */
-	gchar	*cf_name;   /* The cache file's basename.     */
-	gchar	*cf_subdir; /* The cache file's subdirectory. */
+	FILE		*cf_file;   /* The cache file's IO stream.    */
+	const gchar	*cf_name;   /* The cache file's basename.     */
+	const gchar	*cf_subdir; /* The cache file's subdirectory. */
 };
 
 /* Initialize a new file object. */
 void file_init(struct file *, const gchar *, unsigned int);
-void cache_file_init(struct cache_file *, gchar *, gchar *);
+void cache_file_init(struct cache_file *, const gchar *, const gchar *);
 
 /*
  * Returns the full path of the file or an empty string if filename is not set.