diff --git a/apps/openmw/mwsound/ffmpeg_decoder.hpp b/apps/openmw/mwsound/ffmpeg_decoder.hpp
index 0af9a77d98..c51639a972 100644
--- a/apps/openmw/mwsound/ffmpeg_decoder.hpp
+++ b/apps/openmw/mwsound/ffmpeg_decoder.hpp
@@ -24,7 +24,7 @@ extern "C"
     #pragma warning (pop)
 #endif
 
-#include <components/files/constrainedfilestream.hpp>
+#include <components/files/istreamptr.hpp>
 
 #include <string>
 
diff --git a/components/bsa/bsa_file.cpp b/components/bsa/bsa_file.cpp
index 02c70d29cb..9fc6448c2b 100644
--- a/components/bsa/bsa_file.cpp
+++ b/components/bsa/bsa_file.cpp
@@ -23,6 +23,8 @@
 
 #include "bsa_file.hpp"
 
+#include <components/files/constrainedfilestream.hpp>
+
 #include <algorithm>
 #include <cassert>
 #include <cstring>
@@ -256,6 +258,11 @@ void Bsa::BSAFile::close()
     mIsLoaded = false;
 }
 
+Files::IStreamPtr Bsa::BSAFile::getFile(const FileStruct *file)
+{
+    return Files::openConstrainedFileStream(mFilename, file->offset, file->fileSize);
+}
+
 void Bsa::BSAFile::addFile(const std::string& filename, std::istream& file)
 {
     if (!mIsLoaded)
diff --git a/components/bsa/bsa_file.hpp b/components/bsa/bsa_file.hpp
index 66c8234bbd..f6af2e3269 100644
--- a/components/bsa/bsa_file.hpp
+++ b/components/bsa/bsa_file.hpp
@@ -28,8 +28,7 @@
 #include <string>
 #include <vector>
 
-#include <components/files/constrainedfilestream.hpp>
-
+#include <components/files/istreamptr.hpp>
 
 namespace Bsa
 {
@@ -123,10 +122,7 @@ public:
     /** Open a file contained in the archive.
      * @note Thread safe.
     */
-    Files::IStreamPtr getFile(const FileStruct *file)
-    {
-        return Files::openConstrainedFileStream(mFilename, file->offset, file->fileSize);
-    }
+    Files::IStreamPtr getFile(const FileStruct *file);
 
     void addFile(const std::string& filename, std::istream& file);
 
diff --git a/components/bsa/compressedbsafile.cpp b/components/bsa/compressedbsafile.cpp
index ee3a5a0a80..67e172e3db 100644
--- a/components/bsa/compressedbsafile.cpp
+++ b/components/bsa/compressedbsafile.cpp
@@ -47,6 +47,7 @@
 #include <boost/iostreams/device/array.hpp>
 #include <components/bsa/memorystream.hpp>
 #include <components/misc/stringops.hpp>
+#include <components/files/constrainedfilestream.hpp>
 
 namespace Bsa
 {
diff --git a/components/esm/reader.hpp b/components/esm/reader.hpp
index fc3845d87e..a1ddf35641 100644
--- a/components/esm/reader.hpp
+++ b/components/esm/reader.hpp
@@ -3,7 +3,6 @@
 
 #include <vector>
 
-#include <components/files/constrainedfilestream.hpp>
 #include <components/to_utf8/to_utf8.hpp>
 
 #include "common.hpp" // MasterData
diff --git a/components/esm4/reader.cpp b/components/esm4/reader.cpp
index 72421711af..3c0ac470c4 100644
--- a/components/esm4/reader.cpp
+++ b/components/esm4/reader.cpp
@@ -49,6 +49,7 @@
 
 #include <components/bsa/memorystream.hpp>
 #include <components/misc/stringops.hpp>
+#include <components/files/constrainedfilestream.hpp>
 
 #include "formid.hpp"
 
@@ -182,6 +183,16 @@ void Reader::open(Files::IStreamPtr&& stream, const std::string &filename)
     throw std::runtime_error("Unknown file format"); // can't yet use fail() as mCtx is not setup
 }
 
+void Reader::openRaw(const std::string& filename)
+{
+    openRaw(Files::openConstrainedFileStream(filename), filename);
+}
+
+void Reader::open(const std::string& filename)
+{
+    open(Files::openConstrainedFileStream(filename), filename);
+}
+
 void Reader::setRecHeaderSize(const std::size_t size)
 {
     mCtx.recHeaderSize = size;
diff --git a/components/esm4/reader.hpp b/components/esm4/reader.hpp
index aaebeb335a..d4979d034a 100644
--- a/components/esm4/reader.hpp
+++ b/components/esm4/reader.hpp
@@ -26,11 +26,14 @@
 #include <map>
 #include <cstddef>
 #include <memory>
+#include <istream>
 
 #include "common.hpp"
 #include "loadtes4.hpp"
 #include "../esm/reader.hpp"
 
+#include <components/files/istreamptr.hpp>
+
 namespace ESM4 {
     //                                                   bytes read from group, updated by
     //                                                   getRecordHeader() in advance
@@ -129,15 +132,9 @@ namespace ESM4 {
         ~Reader();
 
         // FIXME: should be private but ESMTool uses it
-        void openRaw(const std::string& filename)
-        {
-            openRaw(Files::openConstrainedFileStream(filename), filename);
-        }
+        void openRaw(const std::string& filename);
 
-        void open(const std::string& filename)
-        {
-            open(Files::openConstrainedFileStream(filename), filename);
-        }
+        void open(const std::string& filename);
 
         void close() final;
 
diff --git a/components/files/constrainedfilestream.hpp b/components/files/constrainedfilestream.hpp
index c32c719f22..f00bd3a488 100644
--- a/components/files/constrainedfilestream.hpp
+++ b/components/files/constrainedfilestream.hpp
@@ -3,9 +3,8 @@
 
 #include "constrainedfilestreambuf.hpp"
 #include "streamwithbuffer.hpp"
+#include "istreamptr.hpp"
 
-#include <iosfwd>
-#include <memory>
 #include <limits>
 #include <string>
 
@@ -15,8 +14,6 @@ namespace Files
 /// A file stream constrained to a specific region in the file, specified by the 'start' and 'length' parameters.
 using ConstrainedFileStream = StreamWithBuffer<ConstrainedFileStreamBuf>;
 
-typedef std::unique_ptr<std::istream> IStreamPtr;
-
 IStreamPtr openConstrainedFileStream(const std::string& filename, std::size_t start = 0,
     std::size_t length = std::numeric_limits<std::size_t>::max());
 
diff --git a/components/files/istreamptr.hpp b/components/files/istreamptr.hpp
new file mode 100644
index 0000000000..6dee8b7a60
--- /dev/null
+++ b/components/files/istreamptr.hpp
@@ -0,0 +1,12 @@
+#ifndef OPENMW_COMPONENTS_FILES_ISTREAMPTR_H
+#define OPENMW_COMPONENTS_FILES_ISTREAMPTR_H
+
+#include <iosfwd>
+#include <memory>
+
+namespace Files
+{
+    using IStreamPtr = std::unique_ptr<std::istream>;
+}
+
+#endif
diff --git a/components/nif/niffile.hpp b/components/nif/niffile.hpp
index aa53f516fd..358428e94c 100644
--- a/components/nif/niffile.hpp
+++ b/components/nif/niffile.hpp
@@ -6,9 +6,10 @@
 #include <stdexcept>
 #include <vector>
 #include <atomic>
+#include <limits>
 
 #include <components/debug/debuglog.hpp>
-#include <components/files/constrainedfilestream.hpp>
+#include <components/files/istreamptr.hpp>
 
 #include "record.hpp"
 
diff --git a/components/nif/nifstream.hpp b/components/nif/nifstream.hpp
index 04583131b9..acf1dd4704 100644
--- a/components/nif/nifstream.hpp
+++ b/components/nif/nifstream.hpp
@@ -9,8 +9,9 @@
 #include <vector>
 #include <typeinfo>
 #include <type_traits>
+#include <istream>
 
-#include <components/files/constrainedfilestream.hpp>
+#include <components/files/istreamptr.hpp>
 #include <components/misc/endianness.hpp>
 
 #include <osg/Vec3f>
diff --git a/components/vfs/archive.hpp b/components/vfs/archive.hpp
index faefe30dfe..22df09e06c 100644
--- a/components/vfs/archive.hpp
+++ b/components/vfs/archive.hpp
@@ -3,7 +3,7 @@
 
 #include <map>
 
-#include <components/files/constrainedfilestream.hpp>
+#include <components/files/istreamptr.hpp>
 
 namespace VFS
 {
diff --git a/components/vfs/bsaarchive.cpp b/components/vfs/bsaarchive.cpp
index d4d1a5a38b..c0db4c071c 100644
--- a/components/vfs/bsaarchive.cpp
+++ b/components/vfs/bsaarchive.cpp
@@ -2,6 +2,7 @@
 
 #include <memory>
 #include <algorithm>
+#include <istream>
 
 namespace VFS
 {
diff --git a/components/vfs/filesystemarchive.cpp b/components/vfs/filesystemarchive.cpp
index 8b74fb788a..7b57c93944 100644
--- a/components/vfs/filesystemarchive.cpp
+++ b/components/vfs/filesystemarchive.cpp
@@ -5,6 +5,7 @@
 #include <filesystem>
 
 #include <components/debug/debuglog.hpp>
+#include <components/files/constrainedfilestream.hpp>
 
 namespace VFS
 {
diff --git a/components/vfs/filesystemarchive.hpp b/components/vfs/filesystemarchive.hpp
index fa9b50edc5..2c50e5300b 100644
--- a/components/vfs/filesystemarchive.hpp
+++ b/components/vfs/filesystemarchive.hpp
@@ -3,6 +3,8 @@
 
 #include "archive.hpp"
 
+#include <string>
+
 namespace VFS
 {
 
diff --git a/components/vfs/manager.cpp b/components/vfs/manager.cpp
index bd7418d4b5..4a3ff94cc1 100644
--- a/components/vfs/manager.cpp
+++ b/components/vfs/manager.cpp
@@ -1,6 +1,7 @@
 #include "manager.hpp"
 
 #include <stdexcept>
+#include <istream>
 
 #include <components/misc/stringops.hpp>
 
diff --git a/components/vfs/manager.hpp b/components/vfs/manager.hpp
index bb1ee6ad39..93023f565f 100644
--- a/components/vfs/manager.hpp
+++ b/components/vfs/manager.hpp
@@ -1,11 +1,12 @@
 #ifndef OPENMW_COMPONENTS_RESOURCEMANAGER_H
 #define OPENMW_COMPONENTS_RESOURCEMANAGER_H
 
-#include <components/files/constrainedfilestream.hpp>
+#include <components/files/istreamptr.hpp>
 
 #include <vector>
 #include <map>
 #include <memory>
+#include <string>
 
 namespace VFS
 {