diff -rupN --no-dereference OpenSceneGraph-OpenSceneGraph-3.6.5/CMakeLists.txt OpenSceneGraph-OpenSceneGraph-3.6.5-new/CMakeLists.txt
--- OpenSceneGraph-OpenSceneGraph-3.6.5/CMakeLists.txt	2021-11-13 21:34:02.520773203 +0100
+++ OpenSceneGraph-OpenSceneGraph-3.6.5-new/CMakeLists.txt	2021-11-13 21:34:03.101774222 +0100
@@ -742,7 +742,19 @@ ELSE()
     FIND_PACKAGE(ilmbase)
     FIND_PACKAGE(Inventor)
     FIND_PACKAGE(Jasper)
-    FIND_PACKAGE(OpenEXR)
+    FIND_PACKAGE(Imath CONFIG)
+    IF(TARGET Imath::Imath)
+    FIND_PACKAGE(OpenEXR REQUIRED CONFIG)
+        SET(OPENEXR_LIBRARIES OpenEXR::OpenEXR Imath::Imath)
+        SET(OPENEXR_LIBRARIES_VARS "${OPENEXR_LIBRARIES}")
+            GET_TARGET_PROPERTY(OPENEXR_INCLUDE_DIR OpenEXR::OpenEXRConfig INTERFACE_INCLUDE_DIRECTORIES)
+            GET_TARGET_PROPERTY(IMATH_INCLUDE_DIR Imath::ImathConfig INTERFACE_INCLUDE_DIRECTORIES)
+            LIST(APPEND OPENEXR_INCLUDE_DIR ${IMATH_INCLUDE_DIR})
+            MESSAGE(STATUS "OpenEXR/Imath libraries: " ${OPENEXR_LIBRARIES})
+            SET(OPENEXR_FOUND TRUE)
+    ELSE()
+        FIND_PACKAGE(OpenEXR)
+    ENDIF()
     FIND_PACKAGE(OpenCascade)
     FIND_PACKAGE(COLLADA)
     FIND_PACKAGE(FBX)
diff -rupN --no-dereference OpenSceneGraph-OpenSceneGraph-3.6.5/CMakeModules/FindOpenEXR.cmake OpenSceneGraph-OpenSceneGraph-3.6.5-new/CMakeModules/FindOpenEXR.cmake
--- OpenSceneGraph-OpenSceneGraph-3.6.5/CMakeModules/FindOpenEXR.cmake	2020-01-31 12:03:07.000000000 +0100
+++ OpenSceneGraph-OpenSceneGraph-3.6.5-new/CMakeModules/FindOpenEXR.cmake	2021-11-13 21:34:03.101774222 +0100
@@ -23,6 +23,7 @@ FIND_PATH(OPENEXR_INCLUDE_DIR OpenEXR/Im
     /opt/include
     /usr/freeware/include
 )
+SET(OPENEXR_INCLUDE_DIR ${OPENEXR_INCLUDED_DIR}/OpenEXR)
 
 # Macro to find exr libraries (deduplicating search paths)
 # example: OPENEXR_FIND_VAR(OPENEXR_IlmImf_LIBRARY IlmImf)
diff -rupN --no-dereference OpenSceneGraph-OpenSceneGraph-3.6.5/src/osgPlugins/exr/CMakeLists.txt OpenSceneGraph-OpenSceneGraph-3.6.5-new/src/osgPlugins/exr/CMakeLists.txt
--- OpenSceneGraph-OpenSceneGraph-3.6.5/src/osgPlugins/exr/CMakeLists.txt	2020-01-31 12:03:07.000000000 +0100
+++ OpenSceneGraph-OpenSceneGraph-3.6.5-new/src/osgPlugins/exr/CMakeLists.txt	2021-11-13 21:34:03.102774224 +0100
@@ -12,3 +12,8 @@ ENDIF()
 
 #### end var setup  ###
 SETUP_PLUGIN(exr)
+
+# Force linking with OpenEXR/Imath until upstream fixes their config.
+if(TARGET Imath::Imath)
+    target_link_libraries(osgdb_exr OpenEXR::OpenEXR Imath::Imath)
+endif()
diff -rupN --no-dereference OpenSceneGraph-OpenSceneGraph-3.6.5/src/osgPlugins/exr/ReaderWriterEXR.cpp OpenSceneGraph-OpenSceneGraph-3.6.5-new/src/osgPlugins/exr/ReaderWriterEXR.cpp
--- OpenSceneGraph-OpenSceneGraph-3.6.5/src/osgPlugins/exr/ReaderWriterEXR.cpp	2020-01-31 12:03:07.000000000 +0100
+++ OpenSceneGraph-OpenSceneGraph-3.6.5-new/src/osgPlugins/exr/ReaderWriterEXR.cpp	2021-11-13 21:34:03.102774224 +0100
@@ -41,11 +41,11 @@ public:
       {
         return _inStream->read(c,n).good();
       };
-      virtual Int64    tellg ()
+      virtual uint64_t    tellg ()
       {
           return _inStream->tellg();
       };
-      virtual void    seekg (Int64 pos)
+      virtual void    seekg (uint64_t pos)
       {
         _inStream->seekg(pos);
       };
@@ -69,11 +69,11 @@ public:
       {
         _outStream->write(c,n);
       };
-      virtual Int64    tellp ()
+      virtual uint64_t    tellp ()
       {
         return _outStream->tellp();
       };
-      virtual void seekp (Int64 pos)
+      virtual void seekp (uint64_t pos)
       {
         _outStream->seekp(pos);
       };