diff --git a/meson.build b/meson.build
index ea2de60..cfaaf28 100644
--- a/meson.build
+++ b/meson.build
@@ -128,6 +128,34 @@
 
 blobs_dep = dependency('phosphor-ipmi-blobs')
 
+cpp = meson.get_compiler('cpp')
+# Function2 might not have a pkg-config. It is header only so just make
+# sure we can access the needed symbols from the header.
+function2_dep = dependency('function2', required: false)
+has_function2 = cpp.has_header_symbol(
+  'function2/function2.hpp',
+  'fu2::unique_function',
+  dependencies: function2_dep,
+  required: false)
+if not has_function2
+  function2_opts = import('cmake').subproject_options()
+  function2_opts.add_cmake_defines({'BUILD_TESTING': 'OFF'})
+  function2_proj = import('cmake').subproject(
+    'function2',
+    options: function2_opts,
+    required: false)
+  assert(function2_proj.found(), 'function2 is required')
+  if function2_proj.found()
+    function2_dep = function2_proj.dependency('function2')
+  endif
+endif
+
+if cpp.has_header('nlohmann/json.hpp')
+    json_dep = declare_dependency()
+else
+    json_dep = dependency('nlohmann_json')
+endif
+
 if not get_option('tests').disabled()
   gtest = dependency('gtest', main: true, disabler: true, required: false)
   gmock = dependency('gmock', disabler: true, required: false)