diff --git a/taglib/mp4/mp4file.cpp b/taglib/mp4/mp4file.cpp
index 21a5429b..1e4bd4db 100644
--- a/taglib/mp4/mp4file.cpp
+++ b/taglib/mp4/mp4file.cpp
@@ -129,6 +129,11 @@ MP4::File::read(bool readProperties, Properties::ReadStyle audioPropertiesStyle)
 bool
 MP4::File::save()
 {
+  if(readOnly()) {
+    debug("MP4::File::save() -- File is read only.");
+    return false;
+  }
+
   if(!isValid())
     return false;