diff --git a/SuperBuild.cmake b/SuperBuild.cmake
index d41153c48..1b4266f99 100644
--- a/SuperBuild.cmake
+++ b/SuperBuild.cmake
@@ -301,6 +301,7 @@ ExternalProject_Add(${proj}
     ${CMAKE_OSX_EXTERNAL_PROJECT_ARGS}
     ${COMMON_EXTERNAL_PROJECT_ARGS}
     -D${LOCAL_PROJECT_NAME}_SUPERBUILD:BOOL=OFF
+    -DCMAKE_GENERATOR_PLATFORM:STRING=${CMAKE_GENERATOR_PLATFORM}
   INSTALL_COMMAND ""
   )
 
diff --git a/SuperBuild/External_ITKv5.cmake b/SuperBuild/External_ITKv5.cmake
index bfac43e27..3fac08b0f 100644
--- a/SuperBuild/External_ITKv5.cmake
+++ b/SuperBuild/External_ITKv5.cmake
@@ -171,6 +171,7 @@ if(NOT DEFINED ${extProjName}_DIR AND NOT ${USE_SYSTEM_${extProjName}})
       ${CMAKE_OSX_EXTERNAL_PROJECT_ARGS}
       ${COMMON_EXTERNAL_PROJECT_ARGS}
       ${${proj}_CMAKE_OPTIONS}
+      -DCMAKE_GENERATOR_PLATFORM:STRING=${CMAKE_GENERATOR_PLATFORM}
 ## We really do want to install in order to limit # of include paths INSTALL_COMMAND ""
     DEPENDS
       ${${proj}_DEPENDENCIES}
diff --git a/SuperBuild/External_KWStyle.cmake b/SuperBuild/External_KWStyle.cmake
index 9e46cbdff..f9768e68b 100644
--- a/SuperBuild/External_KWStyle.cmake
+++ b/SuperBuild/External_KWStyle.cmake
@@ -70,6 +70,7 @@ if(NOT DEFINED ${extProjName}_EXE AND NOT ${USE_SYSTEM_${extProjName}})
       ${CMAKE_OSX_EXTERNAL_PROJECT_ARGS}
       ${COMMON_EXTERNAL_PROJECT_ARGS}
       ${${proj}_CMAKE_OPTIONS}
+      -DCMAKE_GENERATOR_PLATFORM:STRING=${CMAKE_GENERATOR_PLATFORM}
     INSTALL_COMMAND ""
     DEPENDS
       ${${proj}_DEPENDENCIES}
diff --git a/SuperBuild/External_SlicerExecutionModel.cmake b/SuperBuild/External_SlicerExecutionModel.cmake
index 06369a4ea..7a4ddcfd2 100644
--- a/SuperBuild/External_SlicerExecutionModel.cmake
+++ b/SuperBuild/External_SlicerExecutionModel.cmake
@@ -85,6 +85,7 @@ if(NOT ( DEFINED "${extProjName}_DIR" OR ( DEFINED "${USE_SYSTEM_${extProjName}}
       ${CMAKE_OSX_EXTERNAL_PROJECT_ARGS}
       ${COMMON_EXTERNAL_PROJECT_ARGS}
       ${${proj}_CMAKE_OPTIONS}
+      -DCMAKE_GENERATOR_PLATFORM:STRING=${CMAKE_GENERATOR_PLATFORM}
     INSTALL_COMMAND ""
     DEPENDS
       ${${proj}_DEPENDENCIES}
diff --git a/SuperBuild/External_VTK.cmake b/SuperBuild/External_VTK.cmake
index a251eeece..fb22ceda7 100644
--- a/SuperBuild/External_VTK.cmake
+++ b/SuperBuild/External_VTK.cmake
@@ -179,6 +179,7 @@ if(NOT ( DEFINED "USE_SYSTEM_${extProjName}" AND "${USE_SYSTEM_${extProjName}}"
       ${CMAKE_OSX_EXTERNAL_PROJECT_ARGS}
       ${COMMON_EXTERNAL_PROJECT_ARGS}
       ${${proj}_CMAKE_OPTIONS}
+      -DCMAKE_GENERATOR_PLATFORM:STRING=${CMAKE_GENERATOR_PLATFORM}
 ## We really do want to install in order to limit # of include paths INSTALL_COMMAND ""
     DEPENDS
       ${${proj}_DEPENDENCIES}