diff --git a/tests/ziptests.nim b/tests/ziptests.nim
index b599a5f..f80ff9a 100644
--- a/tests/ziptests.nim
+++ b/tests/ziptests.nim
@@ -8,6 +8,8 @@ test "can compile zipfiles":
 
 test "zipfiles extractAll":
   var filename = "files/тест.xlsx"
+  if not fileExists(filename):
+    filename = "tests/files/тест.xlsx"
   var z: ZipArchive
   if not z.open(filename):
     echo "Opening zip failed"
@@ -35,6 +37,11 @@ test "zipfiles read and write using Stream":
 
   check: outStream.data == "content"
 
+test "non-zip file raises exception":
+  expect IOError:
+    var z: ZipArchive
+    check (not z.open("zzzzzzzz"))
+
 test "zipfiles read and write archive comment":
   let filename = getTempDir() / "zipfiles_test_archive.zip"
   defer: filename.removeFile
diff --git a/zip/zipfiles.nim b/zip/zipfiles.nim
index 0009ede..d025dc4 100644
--- a/zip/zipfiles.nim
+++ b/zip/zipfiles.nim
@@ -39,6 +39,14 @@ proc open*(z: var ZipArchive, filename: string, mode: FileMode = fmRead): bool =
   z.w = zip_open(filename, flags, addr(err))
   z.mode = mode
   result = z.w != nil
+  if err != 0:
+    var e: ref IOError
+    new(e)
+    var buf = newString(256)
+    var l = zip_error_to_str(buf.cstring, 256.csize, err.cint, 0)
+    buf.setLen(l)
+    e.msg = buf
+    raise e
 
 proc close*(z: var ZipArchive) =
   ## Closes a zip file.