diff --git a/taglib/mp4/mp4atom.cpp b/taglib/mp4/mp4atom.cpp
index 0962a3a5..574fa7a8 100644
--- a/taglib/mp4/mp4atom.cpp
+++ b/taglib/mp4/mp4atom.cpp
@@ -148,7 +148,7 @@ MP4::Atom::find(const char *name1, const char *name2, const char *name3, const c
 }
 
 MP4::AtomList
-MP4::Atom::findall(const char *name, bool recursive)
+MP4::Atom::findall(const char *name, bool recursive) const
 {
   MP4::AtomList result;
   for(const auto &child : std::as_const(d->children)) {
@@ -240,7 +240,7 @@ MP4::Atoms::Atoms(File *file) :
 MP4::Atoms::~Atoms() = default;
 
 MP4::Atom *
-MP4::Atoms::find(const char *name1, const char *name2, const char *name3, const char *name4)
+MP4::Atoms::find(const char *name1, const char *name2, const char *name3, const char *name4) const
 {
   auto it = std::find_if(d->atoms.cbegin(), d->atoms.cend(),
       [&name1](Atom *atom) { return atom->name() == name1; });
@@ -248,7 +248,7 @@ MP4::Atoms::find(const char *name1, const char *name2, const char *name3, const
 }
 
 MP4::AtomList
-MP4::Atoms::path(const char *name1, const char *name2, const char *name3, const char *name4)
+MP4::Atoms::path(const char *name1, const char *name2, const char *name3, const char *name4) const
 {
   MP4::AtomList path;
   auto it = std::find_if(d->atoms.cbegin(), d->atoms.cend(),
diff --git a/taglib/mp4/mp4atom.h b/taglib/mp4/mp4atom.h
index 4fbf9e2d..7a093fcc 100644
--- a/taglib/mp4/mp4atom.h
+++ b/taglib/mp4/mp4atom.h
@@ -82,7 +82,7 @@ namespace TagLib {
       Atom &operator=(const Atom &) = delete;
       Atom *find(const char *name1, const char *name2 = nullptr, const char *name3 = nullptr, const char *name4 = nullptr);
       bool path(AtomList &path, const char *name1, const char *name2 = nullptr, const char *name3 = nullptr);
-      AtomList findall(const char *name, bool recursive = false);
+      AtomList findall(const char *name, bool recursive = false) const;
       void addToOffset(offset_t delta);
       void prependChild(Atom *atom);
       bool removeChild(Atom *meta);
@@ -105,8 +105,8 @@ namespace TagLib {
       ~Atoms();
       Atoms(const Atoms &) = delete;
       Atoms &operator=(const Atoms &) = delete;
-      Atom *find(const char *name1, const char *name2 = nullptr, const char *name3 = nullptr, const char *name4 = nullptr);
-      AtomList path(const char *name1, const char *name2 = nullptr, const char *name3 = nullptr, const char *name4 = nullptr);
+      Atom *find(const char *name1, const char *name2 = nullptr, const char *name3 = nullptr, const char *name4 = nullptr) const;
+      AtomList path(const char *name1, const char *name2 = nullptr, const char *name3 = nullptr, const char *name4 = nullptr) const;
       bool checkRootLevelAtoms();
       const AtomList &atoms() const;
 
diff --git a/taglib/mp4/mp4properties.cpp b/taglib/mp4/mp4properties.cpp
index 8fd398a4..2e9e4135 100644
--- a/taglib/mp4/mp4properties.cpp
+++ b/taglib/mp4/mp4properties.cpp
@@ -125,7 +125,7 @@ MP4::Properties::codec() const
 ////////////////////////////////////////////////////////////////////////////////
 
 void
-MP4::Properties::read(File *file, Atoms *atoms)
+MP4::Properties::read(File *file, const Atoms *atoms)
 {
   MP4::Atom *moov = atoms->find("moov");
   if(!moov) {
diff --git a/taglib/mp4/mp4properties.h b/taglib/mp4/mp4properties.h
index c6ba57a6..6b6b5242 100644
--- a/taglib/mp4/mp4properties.h
+++ b/taglib/mp4/mp4properties.h
@@ -88,7 +88,7 @@ namespace TagLib {
       Codec codec() const;
 
     private:
-      void read(File *file, Atoms *atoms);
+      void read(File *file, const Atoms *atoms);
 
       class PropertiesPrivate;
       TAGLIB_MSVC_SUPPRESS_WARNING_NEEDS_TO_HAVE_DLL_INTERFACE
diff --git a/tests/test_riff.cpp b/tests/test_riff.cpp
index ef8d5261..e57ebacb 100644
--- a/tests/test_riff.cpp
+++ b/tests/test_riff.cpp
@@ -41,27 +41,27 @@ public:
   PublicRIFF(FileName file) : RIFF::File(file, BigEndian)
   {
   }
-  unsigned int riffSize()
+  unsigned int riffSize() const
   {
     return RIFF::File::riffSize();
   }
-  unsigned int chunkCount()
+  unsigned int chunkCount() const
   {
     return RIFF::File::chunkCount();
   }
-  offset_t chunkOffset(unsigned int i)
+  offset_t chunkOffset(unsigned int i) const
   {
     return RIFF::File::chunkOffset(i);
   }
-  unsigned int chunkPadding(unsigned int i)
+  unsigned int chunkPadding(unsigned int i) const
   {
     return RIFF::File::chunkPadding(i);
   }
-  unsigned int chunkDataSize(unsigned int i)
+  unsigned int chunkDataSize(unsigned int i) const
   {
     return RIFF::File::chunkDataSize(i);
   }
-  ByteVector chunkName(unsigned int i)
+  ByteVector chunkName(unsigned int i) const
   {
     return RIFF::File::chunkName(i);
   }
diff --git a/tests/test_tag_c.cpp b/tests/test_tag_c.cpp
index 3068cda9..dc51028a 100644
--- a/tests/test_tag_c.cpp
+++ b/tests/test_tag_c.cpp
@@ -39,7 +39,7 @@ using namespace TagLib;
 namespace {
 
 void propertiesToMap(
-  TagLib_File *file,
+  const TagLib_File *file,
   std::unordered_map<std::string, std::list<std::string>> &propertyMap)
 {
   if(char **keys = taglib_property_keys(file)) {
@@ -59,7 +59,7 @@ void propertiesToMap(
 }
 
 void complexPropertyKeysToList(
-  TagLib_File *file,
+  const TagLib_File *file,
   std::list<std::string> &keyList)
 {
   if(char **complexKeys = taglib_complex_property_keys(file)) {