diff --git a/Rez/Rez.cc b/Rez/Rez.cc
index 5b24e4554f..a6a247a1ab 100644
--- a/Rez/Rez.cc
+++ b/Rez/Rez.cc
@@ -136,6 +136,18 @@ int main(int argc, const char *argv[])
                         for(std::string path : options["include"].as<std::vector<std::string>>())
                             lexer.addIncludePath(path);
 
+                    if(const char *path = getenv("REZ_INCLUDE_PATH"))
+                    {
+                        while(const char* end = strchr(path, ':'))
+                        {
+                            if(end != path)
+                                lexer.addIncludePath(std::string(path, end));
+                            path = end + 1;
+                        }
+                        if(*path)
+                            lexer.addIncludePath(path);
+                    }
+
                     if(world.verboseFlag)
                     {
                         std::cerr << "Compiling " << fn << "...\n";
diff --git a/cmake/add_application.cmake b/cmake/add_application.cmake
index c899af741e..1a723dc286 100644
--- a/cmake/add_application.cmake
+++ b/cmake/add_application.cmake
@@ -23,11 +23,15 @@ function(add_application name)
     set(files)
     set(rsrc_files)
     set(rez_files)
+
+    set(rez_include_options ${REZ_INCLUDE_PATH})
+    list(TRANSFORM rez_include_options PREPEND -I)
+
     foreach(f ${ARGS_FILES})
         if(${f} MATCHES "\\.r$")
             add_custom_command(
                 OUTPUT ${f}.rsrc.bin
-                COMMAND ${REZ} ${REZ_FLAGS} ${CMAKE_CURRENT_SOURCE_DIR}/${f} -I ${REZ_INCLUDE_PATH} -o ${f}.rsrc.bin
+                COMMAND ${REZ} ${REZ_FLAGS} ${CMAKE_CURRENT_SOURCE_DIR}/${f} ${rez_include_options} -o ${f}.rsrc.bin
                 DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/${f})
             list(APPEND rsrc_files "${CMAKE_CURRENT_BINARY_DIR}/${f}.rsrc.bin")
             list(APPEND rez_files "${f}")
diff --git a/flake.nix b/flake.nix
index e4946fdbc3..8f8eb73257 100644
--- a/flake.nix
+++ b/flake.nix
@@ -241,7 +241,6 @@
                 set(CMAKE_CROSSCOMPILING TRUE)
 
                 set( REZ "${pkgs.buildPackages.retro68_tools}/bin/Rez" )
-                set( REZ_INCLUDE_PATH "${pkgs.multiversal}/RIncludes" )
 
                 include(${self + "/cmake/add_application.cmake"})
               '';
@@ -250,6 +249,25 @@
               name = "retro68_setup_hook";
               text = ''
                 export CMAKE_TOOLCHAIN_FILE=${toolchain}
+
+                retro68_addRIncludes() {
+                  echo "retro68_addRIncludes: $1 $depHostOffset"
+                  case $depHostOffset in
+                      -1) local role='BUILD_' ;;
+                      0)  local role="" ;;
+                      1)  local role='TARGET_' ;;
+                      *)  echo "retro68_addRIncludes: Error: Cannot be used with $depHostOffset-offset deps" >2;
+                          return 1 ;;
+                  esac
+
+                  if [[ -d "$1/RIncludes" ]]; then
+                      export REZ_INCLUDE_PATH+=":$1/RIncludes"
+                  fi
+                }
+
+                echo "targetOffset: $targetOffset"
+                addEnvHooks "$targetOffset" retro68_addRIncludes
+
               '' + (pkgs.lib.optionalString (systemName == "Retro68") ''
                 export RETRO68_LD_WRAPPER_Retro68="${pkgs.buildPackages.retro68_tools}/bin/Elf2Mac"
                 export RETRO68_REAL_LD="${pkgs.buildPackages.retro68_binutils}/bin/m68k-apple-macos-ld.real"