diff --git a/taglib/dsdiff/dsdifffile.cpp b/taglib/dsdiff/dsdifffile.cpp
index 35f934cc..6a5cf843 100644
--- a/taglib/dsdiff/dsdifffile.cpp
+++ b/taglib/dsdiff/dsdifffile.cpp
@@ -226,7 +226,7 @@ bool DSDIFF::File::save(int tags, StripTags strip, ID3v2::Version version)
 
   // First: save ID3V2 chunk
 
-  ID3v2::Tag *id3v2Tag = ID3v2Tag();
+  const ID3v2::Tag *id3v2Tag = ID3v2Tag();
 
   if((tags & ID3v2) && id3v2Tag) {
     if(d->isID3InPropChunk) {
@@ -255,7 +255,7 @@ bool DSDIFF::File::save(int tags, StripTags strip, ID3v2::Version version)
 
   // Second: save the DIIN chunk
 
-  DSDIFF::DIIN::Tag *diinTag = DIINTag();
+  const DSDIFF::DIIN::Tag *diinTag = DIINTag();
 
   if((tags & DIIN) && diinTag) {
     if(!diinTag->title().isEmpty()) {
diff --git a/taglib/mp4/mp4properties.cpp b/taglib/mp4/mp4properties.cpp
index 3f8d8d19..8fd398a4 100644
--- a/taglib/mp4/mp4properties.cpp
+++ b/taglib/mp4/mp4properties.cpp
@@ -138,7 +138,7 @@ MP4::Properties::read(File *file, Atoms *atoms)
 
   const MP4::AtomList trakList = moov->findall("trak");
   for(const auto &track : trakList) {
-    MP4::Atom *hdlr = track->find("mdia", "hdlr");
+    const MP4::Atom *hdlr = track->find("mdia", "hdlr");
     if(!hdlr) {
       debug("MP4: Atom 'trak.mdia.hdlr' not found");
       return;
@@ -156,7 +156,7 @@ MP4::Properties::read(File *file, Atoms *atoms)
     return;
   }
 
-  MP4::Atom *mdhd = trak->find("mdia", "mdhd");
+  const MP4::Atom *mdhd = trak->find("mdia", "mdhd");
   if(!mdhd) {
     debug("MP4: Atom 'trak.mdia.mdhd' not found");
     return;
@@ -186,7 +186,7 @@ MP4::Properties::read(File *file, Atoms *atoms)
   }
   if(length == 0) {
     // No length found in the media header (mdhd), try the movie header (mvhd)
-    if(MP4::Atom *mvhd = moov->find("mvhd")) {
+    if(const MP4::Atom *mvhd = moov->find("mvhd")) {
       file->seek(mvhd->offset());
       data = file->readBlock(mvhd->length());
       if(data.size() >= 24 + 4) {
diff --git a/taglib/mp4/mp4tag.cpp b/taglib/mp4/mp4tag.cpp
index 85fa6527..42905574 100644
--- a/taglib/mp4/mp4tag.cpp
+++ b/taglib/mp4/mp4tag.cpp
@@ -65,7 +65,7 @@ MP4::Tag::Tag(TagLib::File *file, MP4::Atoms *atoms,
   d->file = file;
   d->atoms = atoms;
 
-  MP4::Atom *ilst = atoms->find("moov", "udta", "meta", "ilst");
+  const MP4::Atom *ilst = atoms->find("moov", "udta", "meta", "ilst");
   if(!ilst) {
     //debug("Atom moov.udta.meta.ilst not found.");
     return;
@@ -268,7 +268,7 @@ MP4::Tag::saveExisting(ByteVector data, const AtomList &path)
   // check if there is an atom before 'ilst', and possibly use it as padding
   if(index != meta->children().cbegin()) {
     auto prevIndex = std::prev(index);
-    MP4::Atom *prev = *prevIndex;
+    const MP4::Atom *prev = *prevIndex;
     if(prev->name() == "free") {
       offset = prev->offset();
       length += prev->length();
@@ -277,7 +277,7 @@ MP4::Tag::saveExisting(ByteVector data, const AtomList &path)
   // check if there is an atom after 'ilst', and possibly use it as padding
   auto nextIndex = std::next(index);
   if(nextIndex != meta->children().cend()) {
-    MP4::Atom *next = *nextIndex;
+    const MP4::Atom *next = *nextIndex;
     if(next->name() == "free") {
       length += next->length();
     }
diff --git a/taglib/tagunion.cpp b/taglib/tagunion.cpp
index d866bdce..22a0215c 100644
--- a/taglib/tagunion.cpp
+++ b/taglib/tagunion.cpp
@@ -106,7 +106,7 @@ void TagUnion::set(int index, Tag *tag)
 
 PropertyMap TagUnion::properties() const
 {
-  auto it = std::find_if(d->tags.cbegin(), d->tags.cend(), [](Tag *t) {
+  auto it = std::find_if(d->tags.cbegin(), d->tags.cend(), [](const Tag *t) {
     return t && !t->isEmpty();
   });
   return it != d->tags.cend() ? (*it)->properties() : PropertyMap();