diff -u -r a/cmake/find/find_boost_ext.cmake b/cmake/find/find_boost_ext.cmake
--- a/cmake/find/find_boost_ext.cmake
+++ b/cmake/find/find_boost_ext.cmake
@@ -38,13 +38,7 @@
     set(Boost_NO_WARN_NEW_VERSIONS ON CACHE INTERNAL "")
     #set(Boost_DEBUG ON)
 
-    if(MDL_BUILD_OPENIMAGEIO_PLUGIN OR MDL_BUILD_CORE_EXAMPLES)
-        # OpenImageIO needs Boost::filesystem and Boost::thread.
-        find_package(Boost COMPONENTS filesystem thread)
-    else()
-        # Otherwise the Boost headers are sufficient.
-        find_package(Boost)
-    endif()
+    find_package(Boost)
 
     set(Boost_FOUND ${Boost_FOUND} CACHE INTERNAL "Dependency boost has been resolved.")
 
diff -u -r a/cmake/find/find_openimageio_ext.cmake b/cmake/find/find_openimageio_ext.cmake
--- a/cmake/find/find_openimageio_ext.cmake
+++ b/cmake/find/find_openimageio_ext.cmake
@@ -4,19 +4,17 @@
 
 function(FIND_OPENIMAGEIO_EXT)
 
-    if(${CMAKE_VERSION} VERSION_LESS "3.19.0")
-        find_package(OpenImageIO)
-        if(OpenImageIO_FOUND)
-            if(${OpenImageIO_VERSION} VERSION_LESS "2.4")
-                set(OpenImageIO_FOUND OFF)
-                message(WARNING "Found OpenImageIO version ${OpenImageIO_VERSION} is too old.")
-            elseif(${OpenImageIO_VERSION} VERSION_GREATER_EQUAL "3.0")
-                set(OpenImageIO_FOUND OFF)
-                message(WARNING "Found OpenImageIO version ${OpenImageIO_VERSION} is too new.")
-            endif()
+    # Explicit code since a version range on find_package() does not support multiple major
+    # versions.
+    find_package(OpenImageIO)
+    if(OpenImageIO_FOUND)
+        if(${OpenImageIO_VERSION} VERSION_LESS "2.4")
+            set(OpenImageIO_FOUND OFF)
+            message(WARNING "Found OpenImageIO version ${OpenImageIO_VERSION} is too old.")
+        elseif(${OpenImageIO_VERSION} VERSION_GREATER_EQUAL "4.0")
+            set(OpenImageIO_FOUND OFF)
+            message(WARNING "Found OpenImageIO version ${OpenImageIO_VERSION} is too new.")
         endif()
-    else()
-        find_package(OpenImageIO 2.4...<3.0)
     endif()
 
     # See https://github.com/microsoft/vcpkg/issues/29284
diff -u -r a/src/shaders/plugin/openimageio/openimageio_utilities.cpp b/src/shaders/plugin/openimageio/openimageio_utilities.cpp
--- a/src/shaders/plugin/openimageio/openimageio_utilities.cpp
+++ b/src/shaders/plugin/openimageio/openimageio_utilities.cpp
@@ -421,14 +421,22 @@
 
     const char* proxytype () const override { return "nv_reader"; }
     void close() override { m_reader.reset(); }
+#if OIIO_VERSION >= OIIO_MAKE_VERSION(3,0,0)
+    int64_t tell() const override { return m_reader->tell_absolute(); }
+#else
     int64_t tell() override { return m_reader->tell_absolute(); }
+#endif
     bool seek( int64_t offset) override { return m_reader->seek_absolute( offset); }
     size_t read( void* buf, size_t size) override;
     size_t write( const void* buf, size_t size) override;
     size_t pread( void* buf, size_t size, int64_t offset) override;
     size_t pwrite( const void* buf, size_t size, int64_t offset) override;
     size_t size() const override { return m_reader->get_file_size(); }
+#if OIIO_VERSION >= OIIO_MAKE_VERSION(3,0,0)
+    void flush() override { }
+#else
     void flush() const override { }
+#endif
 
 private:
     /// The wrapped reader.
@@ -502,14 +510,22 @@
 
     const char* proxytype () const override { return "nv_writer"; }
     void close() override { m_writer.reset(); }
+#if OIIO_VERSION >= OIIO_MAKE_VERSION(3,0,0)
+    int64_t tell() const override { return m_writer->tell_absolute(); }
+#else
     int64_t tell() override { return m_writer->tell_absolute(); }
+#endif
     bool seek( int64_t offset) override { return m_writer->seek_absolute( offset); }
     size_t read( void* buf, size_t size) override;
     size_t write( const void* buf, size_t size) override;
     size_t pread( void* buf, size_t size, int64_t offset) override;
     size_t pwrite( const void* buf, size_t size, int64_t offset) override;
     size_t size() const override { return m_writer->get_file_size(); }
+#if OIIO_VERSION >= OIIO_MAKE_VERSION(3,0,0)
+    void flush() override { m_writer->flush(); }
+#else
     void flush() const override { m_writer->flush(); }
+#endif
 
 private:
     /// The wrapped writer.