diff --git a/taglib/mpeg/id3v2/id3v2frame.cpp b/taglib/mpeg/id3v2/id3v2frame.cpp
index af38a6ff..c99cb16a 100644
--- a/taglib/mpeg/id3v2/id3v2frame.cpp
+++ b/taglib/mpeg/id3v2/id3v2frame.cpp
@@ -92,7 +92,7 @@ const String Frame::urlPrefix("URL:");
 // public members
 ////////////////////////////////////////////////////////////////////////////////
 
-unsigned int Frame::headerSize()
+unsigned int Frame::headerSize() const
 {
   return d->header->size();
 }
@@ -421,7 +421,7 @@ public:
 // public members (Frame::Header)
 ////////////////////////////////////////////////////////////////////////////////
 
-unsigned int Frame::Header::size()
+unsigned int Frame::Header::size() const
 {
   switch(d->version) {
   case 0:
diff --git a/taglib/mpeg/id3v2/id3v2frame.h b/taglib/mpeg/id3v2/id3v2frame.h
index fc2976de..eb8ba5e2 100644
--- a/taglib/mpeg/id3v2/id3v2frame.h
+++ b/taglib/mpeg/id3v2/id3v2frame.h
@@ -85,7 +85,7 @@ namespace TagLib {
       /*!
        * Returns the size of the frame header
        */
-      unsigned int headerSize();
+      unsigned int headerSize() const;
 
       /*!
        * Sets the data that will be used as the frame.  Since the length is not
@@ -360,7 +360,7 @@ namespace TagLib {
       /*!
        * Returns the size of the frame header in bytes.
        */
-      unsigned int size();
+      unsigned int size() const;
 
       /*!
        * Returns \c true if the flag for tag alter preservation is set.