diff --git a/src/cmake/externalpackages.cmake b/src/cmake/externalpackages.cmake
index 8131672..7a6455e 100644
--- a/src/cmake/externalpackages.cmake
+++ b/src/cmake/externalpackages.cmake
@@ -264,15 +264,15 @@ checked_find_package (Nuke)
 checked_find_package (OpenGL)   # used for iv
 
 # Qt -- used for iv
-set (qt5_modules Core Gui Widgets)
+set (qt6_modules Core Gui Widgets)
 if (OPENGL_FOUND)
-    list (APPEND qt5_modules OpenGL)
+    list (APPEND qt6_modules OpenGL OpenGLWidgets)
 endif ()
 option (USE_QT "Use Qt if found" ON)
-checked_find_package (Qt5 COMPONENTS ${qt5_modules})
-if (USE_QT AND NOT Qt5_FOUND AND APPLE)
-    message (STATUS "  If you think you installed qt5 with Homebrew and it still doesn't work,")
-    message (STATUS "  try:   export PATH=/usr/local/opt/qt5/bin:$PATH")
+checked_find_package (Qt6 COMPONENTS ${qt6_modules})
+if (USE_QT AND NOT Qt6_FOUND AND APPLE)
+    message (STATUS "  If you think you installed qt6 with Homebrew and it still doesn't work,")
+    message (STATUS "  try:   export PATH=/usr/local/opt/qt6/bin:$PATH")
 endif ()
 
 
diff --git a/src/iv/CMakeLists.txt b/src/iv/CMakeLists.txt
index 88a2151..cbc4a54 100644
--- a/src/iv/CMakeLists.txt
+++ b/src/iv/CMakeLists.txt
@@ -3,18 +3,18 @@
 # https://github.com/OpenImageIO/oiio
 
 set (CMAKE_AUTOMOC ON)
-if (Qt5_POSITION_INDEPENDENT_CODE)
+if (Qt6_POSITION_INDEPENDENT_CODE)
     set (CMAKE_POSITION_INDEPENDENT_CODE ON)
 endif()
 
 check_is_enabled (iv iv_enabled)
-if (iv_enabled AND Qt5_FOUND AND OPENGL_FOUND)
+if (iv_enabled AND Qt6_FOUND AND OPENGL_FOUND)
     fancy_add_executable (
         SYSTEM_INCLUDE_DIRS
             ${OPENGL_INCLUDE_DIR}
         LINK_LIBRARIES
             OpenImageIO
-            Qt5::Core Qt5::Gui Qt5::Widgets Qt5::OpenGL
+            Qt6::Core Qt6::Gui Qt6::Widgets Qt6::OpenGLWidgets
             ${OPENGL_LIBRARIES}
         )
     if (iv_enabled AND FORCE_OPENGL_1)
diff --git a/src/iv/imageviewer.h b/src/iv/imageviewer.h
index f20b79a..ca67b52 100644
--- a/src/iv/imageviewer.h
+++ b/src/iv/imageviewer.h
@@ -23,7 +23,7 @@
 #include <QAction>
 #include <QCheckBox>
 #include <QDialog>
-#include <QGLWidget>
+#include <QOpenGLWidget>
 #include <QMainWindow>
 
 #ifndef QT_NO_PRINTER