diff --git a/bin/ikarus b/bin/ikarus
index e112280..ec0bfc9 100755
Binary files a/bin/ikarus and b/bin/ikarus differ
diff --git a/bin/ikarus-runtime.c b/bin/ikarus-runtime.c
index 5a8cd35..e321cbb 100644
--- a/bin/ikarus-runtime.c
+++ b/bin/ikarus-runtime.c
@@ -646,7 +646,13 @@ ikrt_file_exists(ikp filename){
 
 ikp
 ikrt_delete_file(ikp filename){
-  char* str = string_data(filename);
+  char* str;
+  if(tagof(filename) == bytevector_tag){
+    str = (char*) filename + off_bytevector_data;
+  } else {
+    fprintf(stderr, "bug in ikrt_delete_file\n");
+    exit(-1);
+  }
   int err = unlink(str);
   if(err == 0){
     return 0;
diff --git a/src/ikarus.boot b/src/ikarus.boot
index 63945cc..3622df0 100644
Binary files a/src/ikarus.boot and b/src/ikarus.boot differ
diff --git a/src/ikarus.posix.ss b/src/ikarus.posix.ss
index 519ace9..0601c36 100644
--- a/src/ikarus.posix.ss
+++ b/src/ikarus.posix.ss
@@ -60,7 +60,8 @@
     (lambda (x)
       (unless (string? x)
         (error 'delete-file "filename ~s is not a string" x))
-      (let ([v (foreign-call "ikrt_delete_file" x)])
+      (let ([v (foreign-call "ikrt_delete_file"
+                 (string->utf8-bytevector x))])
         (case v
           [(0) (void)]
           [else