diff --git a/test/core/ExamplesUnitTests/TribitsExampleProject_Tests.cmake b/test/core/ExamplesUnitTests/TribitsExampleProject_Tests.cmake
index 651ba2f4f..aa4a7dc09 100644
--- a/test/core/ExamplesUnitTests/TribitsExampleProject_Tests.cmake
+++ b/test/core/ExamplesUnitTests/TribitsExampleProject_Tests.cmake
@@ -631,6 +631,7 @@ tribits_add_advanced_test( TribitsExampleProject_NoFortran_reduced_tarball
       -DTribitsExProj_ENABLE_ALL_PACKAGES=ON
       -DTribitsExProj_ENABLE_TESTS=ON
       -DTribitsExProj_ASSERT_DEFINED_DEPENDENCIES=WARNING
+      -DWithSubpackagesB_DISABLE_SUPPORT_FOR_MixedLang=ON
       ../tribitsexproj-1.1-Source
     PASS_REGULAR_EXPRESSION_ALL
       "CMake Warning at .*/tribits/core/package_arch/TribitsProcessPackagesAndDirsLists.cmake"
diff --git a/tribits/core/package_arch/TribitsAdjustPackageEnables.cmake b/tribits/core/package_arch/TribitsAdjustPackageEnables.cmake
index 814533ea3..50457ddd6 100644
--- a/tribits/core/package_arch/TribitsAdjustPackageEnables.cmake
+++ b/tribits/core/package_arch/TribitsAdjustPackageEnables.cmake
@@ -45,6 +45,7 @@ include(TribitsPrintEnabledPackagesLists)
 include(TribitsPrintDependencyInfo)
 include(TribitsPackageDependencies)
 include(TribitsGetPackageEnableStatus)
+include(TribitsGetHavePackageDependencyMacroName)
 
 include(AdvancedOption)
 include(AdvancedSet)
@@ -1189,9 +1190,8 @@ macro(tribits_private_postprocess_optional_package_enable  packageName  optDepPk
       "${optDepPkgEnable} is set!")
   endif()
 
-  string(TOUPPER  ${packageName}  packageName_UPPER)
-  string(TOUPPER  ${optDepPkg}  optDepPkg_UPPER)
-  set(macroDefineName  HAVE_${packageName_UPPER}_${optDepPkg_UPPER})
+  tribits_get_have_package_dependency_macro_name(${packageName} ${optDepPkg}
+    macroDefineName)
 
   if(${packageName}_ENABLE_${optDepPkg})
     set(${macroDefineName} ON)
diff --git a/tribits/core/package_arch/TribitsGetHavePackageDependencyMacroName.cmake b/tribits/core/package_arch/TribitsGetHavePackageDependencyMacroName.cmake
new file mode 100644
index 000000000..cacc5a686
--- /dev/null
+++ b/tribits/core/package_arch/TribitsGetHavePackageDependencyMacroName.cmake
@@ -0,0 +1,9 @@
+function(tribits_get_have_package_dependency_macro_name  packageName  upstreamPackageName
+    haveDepMacroNameOut
+  )
+  string(TOUPPER  ${packageName}  packageName_UC)
+  string(TOUPPER  ${upstreamPackageName}  upstreamPackageName_UC)
+  set(haveDepMacroName
+    HAVE_${packageName_UC}_${upstreamPackageName_UC})
+  set(${haveDepMacroNameOut} ${haveDepMacroName} PARENT_SCOPE)
+endfunction()
diff --git a/tribits/core/package_arch/TribitsPackageMacros.cmake b/tribits/core/package_arch/TribitsPackageMacros.cmake
index d7931c406..e0c331182 100644
--- a/tribits/core/package_arch/TribitsPackageMacros.cmake
+++ b/tribits/core/package_arch/TribitsPackageMacros.cmake
@@ -61,6 +61,7 @@ include(TribitsAddExecutable)
 include(TribitsAddExecutableAndTest)
 include(TribitsCopyFilesToBinaryDir)
 include(TribitsReportInvalidTribitsUsage)
+include(TribitsGetHavePackageDependencyMacroName)
 
 
 #
@@ -415,11 +416,19 @@ endmacro()
 #
 # Usage::
 #
-#   tribits_disable_optional_dependency(<upstreamPackageName>  "<reasonStr>")
+#   tribits_disable_optional_dependency(<upstreamPackageName>  "<reasonStr>"
+#     [PACKAGE_NAME <packageName>] )
 #
-# This macro can be called from a top-level package's
-# ``<packageDir>/CMakeLists.txt`` file to disable an optional dependency that
-# may have been enabled by the user or through automated enable/disable logic.
+# This will disable the dependency of the package ``<packageName>`` on the
+# upstream package ``<upstreamPackageName>``.  If the argument ``PACKAGE_NAME
+# <packageName>`` is missing, then ``<packageName>`` will be
+# ``${PACKAGE_NAME}``.
+#
+# This macro can be called from the top-level package's
+# ``<packageDir>/CMakeLists.txt`` file (or from a subpackages's parent
+# top-level ``<packageDir>/CMakeLists.txt`` if ``<packageName>`` is the name
+# of a subpackage) to disable an optional dependency that may have been
+# enabled by the user or through automated enable/disable logic.
 #
 # This is most useful in cases where multiple criteria must be considered
 # before support for some upstream dependency can really be supported.  In
@@ -427,7 +436,17 @@ endmacro()
 # telegraphed to all downstream packages.  See `How to tweak downstream
 # TriBITS "ENABLE" variables during package configuration`_ for more details.
 #
+# NOTE: The constraint that this must be called from a top-level package's
+# ``<packageDir>/CMakeLists.txt`` is because this macro sets non-cache
+# variables at the base project-level scope.)
+#
 macro(tribits_disable_optional_dependency  upstreamPackageName  reasonStr)
+  cmake_parse_arguments(TDOD_PARSE "" "PACKAGE_NAME" "" ${ARGN})
+  if (TDOD_PARSE_PACKAGE_NAME)
+    set(tdod_packageName ${TDOD_PARSE_PACKAGE_NAME})
+  else()
+    set(tdod_packageName ${PACKAGE_NAME})
+  endif()
   # Assert called in the correct context
   if (NOT "${${PACKAGE_NAME}_PARENT_PACKAGE}" STREQUAL "")
     message(FATAL_ERROR "ERROR: Calling tribits_disable_optional_dependency() from"
@@ -441,11 +460,10 @@ macro(tribits_disable_optional_dependency  upstreamPackageName  reasonStr)
       " '${${PACKAGE_NAME}_SOURCE_DIR}/CMakeLists.txt'" )
   endif()
   # Get the variable names that are going to be set assert they exist already
-  set(packageEnableVarName ${PACKAGE_NAME}_ENABLE_${upstreamPackageName})
+  set(packageEnableVarName ${tdod_packageName}_ENABLE_${upstreamPackageName})
   assert_defined(${packageEnableVarName})
-  string(TOUPPER  ${upstreamPackageName}  upstreamPackageName_UC)
-  set(havePackageUpstreamPackageMacroVarName
-    HAVE_${PACKAGE_NAME_UC}_${upstreamPackageName_UC})
+  tribits_get_have_package_dependency_macro_name(${tdod_packageName}
+    ${upstreamPackageName}  havePackageUpstreamPackageMacroVarName)
   assert_defined(${havePackageUpstreamPackageMacroVarName})
   # Set the variables to OFF in local and project-level scopes
   if (NOT "${reasonStr}" STREQUAL "")
diff --git a/tribits/examples/TribitsExampleProject/packages/with_subpackages/CMakeLists.txt b/tribits/examples/TribitsExampleProject/packages/with_subpackages/CMakeLists.txt
index 53c3811ad..85a468caa 100644
--- a/tribits/examples/TribitsExampleProject/packages/with_subpackages/CMakeLists.txt
+++ b/tribits/examples/TribitsExampleProject/packages/with_subpackages/CMakeLists.txt
@@ -2,6 +2,12 @@ tribits_package_decl(WithSubpackages)
 
 tribits_add_debug_option()
 
+if (WithSubpackagesB_DISABLE_SUPPORT_FOR_MixedLang)
+  tribits_disable_optional_dependency(MixedLang
+    "WithSubpackagesB: Disabling support for MixedLang because WithSubpackagesB_DISABLE_SUPPORT_FOR_MixedLang='${WithSubpackagesB_DISABLE_SUPPORT_FOR_MixedLang}'!"
+    PACKAGE_NAME WithSubpackagesB)
+endif()
+
 tribits_process_subpackages()
 
 tribits_exclude_files(