diff --git a/src/fs/file.c b/src/fs/file.c
index e69ba65..91d2a07 100644
--- a/src/fs/file.c
+++ b/src/fs/file.c
@@ -506,7 +506,7 @@ int meta_add(uint16_t fid, const uint8_t *data, uint16_t len) {
     return PICOKEY_OK;
 }
 
-bool file_has_data(file_t *f) {
+bool file_has_data(const file_t *f) {
     return f != NULL && f->data != NULL && file_get_size(f) > 0;
 }
 
diff --git a/src/fs/file.h b/src/fs/file.h
index 1cb605d..4512f33 100644
--- a/src/fs/file.h
+++ b/src/fs/file.h
@@ -100,7 +100,7 @@ __attribute__ ((packed))
 #endif
 file_t;
 
-extern bool file_has_data(file_t *);
+extern bool file_has_data(const file_t *);
 
 extern file_t *currentEF;
 extern file_t *currentDF;