diff --git a/build.zig b/build.zig
index 424c00c091..b999631951 100644
--- a/build.zig
+++ b/build.zig
@@ -408,6 +408,7 @@ pub fn test_config(b: *std.Build, gen_dir: LazyPath) ![]u8 {
         \\local M = {{}}
         \\
         \\M.include_paths = {{}}
+        \\M.apple_sysroot = ""
         \\M.translations_enabled = "$ENABLE_TRANSLATIONS" == "ON"
         \\M.is_asan = "$ENABLE_ASAN_UBSAN" == "ON"
         \\M.is_zig_build = true
diff --git a/src/nvim/CMakeLists.txt b/src/nvim/CMakeLists.txt
index f6112a3c2a..e59be46314 100644
--- a/src/nvim/CMakeLists.txt
+++ b/src/nvim/CMakeLists.txt
@@ -481,11 +481,13 @@ foreach(target ${targets})
     message(STATUS "${target} props '${prop}'")
     foreach(gen_include ${prop})
       list(APPEND gen_cflags "-I${gen_include}")
+      list(APPEND TEST_INCLUDE_DIRS "${gen_include}")
     endforeach()
   endif()
 endforeach()
 
 list(REMOVE_DUPLICATES gen_cflags)
+list(REMOVE_DUPLICATES TEST_INCLUDE_DIRS)
 
 if(APPLE AND CMAKE_OSX_SYSROOT)
   list(APPEND gen_cflags "-isysroot" "${CMAKE_OSX_SYSROOT}")
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index 8db05ac839..1141e6aded 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -1,6 +1,6 @@
 add_subdirectory(functional/fixtures)  # compile test programs
 
-get_target_property(TEST_INCLUDE_DIRS main_lib INTERFACE_INCLUDE_DIRECTORIES)
+get_directory_property(TEST_INCLUDE_DIRS DIRECTORY ${PROJECT_SOURCE_DIR}/src/nvim DEFINITION TEST_INCLUDE_DIRS)
 
 set(TEST_OPTIONS
       -D BUILD_DIR=${CMAKE_BINARY_DIR}
diff --git a/test/cmakeconfig/paths.lua.in b/test/cmakeconfig/paths.lua.in
index 56d3257bcf..2984200952 100644
--- a/test/cmakeconfig/paths.lua.in
+++ b/test/cmakeconfig/paths.lua.in
@@ -4,6 +4,7 @@ M.include_paths = {}
 for p in ("${TEST_INCLUDE_DIRS}" .. ";"):gmatch("[^;]+") do
   table.insert(M.include_paths, p)
 end
+M.apple_sysroot = "${CMAKE_OSX_SYSROOT}"
 
 M.translations_enabled = "${ENABLE_TRANSLATIONS}" == "ON"
 M.is_asan = "${ENABLE_ASAN_UBSAN}" == "ON"
diff --git a/test/unit/preprocess.lua b/test/unit/preprocess.lua
index 8d481df0d0..6114f43ad7 100644
--- a/test/unit/preprocess.lua
+++ b/test/unit/preprocess.lua
@@ -146,13 +146,20 @@ end
 
 --- @param ... string
 function Gcc:add_to_include_path(...)
+  local ef = self.preprocessor_extra_flags
   for i = 1, select('#', ...) do
     local path = select(i, ...)
-    local ef = self.preprocessor_extra_flags
     ef[#ef + 1] = '-I' .. path
   end
 end
 
+function Gcc:add_apple_sysroot(sysroot)
+  local ef = self.preprocessor_extra_flags
+
+  table.insert(ef, '-isysroot')
+  table.insert(ef, sysroot)
+end
+
 -- returns a list of the headers files upon which this file relies
 --- @param hdr string
 --- @return string[]?
@@ -278,4 +285,9 @@ function M.add_to_include_path(...)
   return cc:add_to_include_path(...)
 end
 
+--- @param ... string
+function M.add_apple_sysroot(...)
+  return cc:add_apple_sysroot(...)
+end
+
 return M
diff --git a/test/unit/testutil.lua b/test/unit/testutil.lua
index a38e602ac8..3c40f7062e 100644
--- a/test/unit/testutil.lua
+++ b/test/unit/testutil.lua
@@ -19,6 +19,11 @@ for _, p in ipairs(paths.include_paths) do
   Preprocess.add_to_include_path(p)
 end
 
+-- add some nonstandard header locations
+if paths.apple_sysroot ~= '' then
+  Preprocess.add_apple_sysroot(paths.apple_sysroot)
+end
+
 local child_pid = nil --- @type integer?
 --- @generic F: function
 --- @param func F