diff --git a/src/tox/tox_env/api.py b/src/tox/tox_env/api.py
index 3ce15b993b..51c57fde3b 100644
--- a/src/tox/tox_env/api.py
+++ b/src/tox/tox_env/api.py
@@ -212,6 +212,8 @@ def _default_pass_env(self) -> list[str]:
             "CURL_CA_BUNDLE",  # curl certificates
             "SSL_CERT_FILE",  # https certificates
             "LD_LIBRARY_PATH",  # location of libs
+            "CC",  # location of compiler
+            "CCSHARED",  # location of compiler files
         ]
         if sys.stdout.isatty():  # if we're on a interactive shell pass on the TERM
             env.append("TERM")
diff --git a/src/tox/tox_env/python/api.py b/src/tox/tox_env/python/api.py
index 9772a9412f..9a8ff6ce3f 100644
--- a/src/tox/tox_env/python/api.py
+++ b/src/tox/tox_env/python/api.py
@@ -118,7 +118,8 @@ def _default_pass_env(self) -> list[str]:
                     "NUMBER_OF_PROCESSORS",  # multiprocessing.cpu_count()
                 ],
             )
-        env.extend(["PKG_CONFIG_PATH"])  # used by binary extensions during installation
+        binary_extension_build = ["PKG_CONFIG", "PKG_CONFIG_PATH", "PKG_CONFIG_SYSROOT_DIR"]
+        env.extend(binary_extension_build)  # used by binary extensions during installation
         env.extend(["REQUESTS_CA_BUNDLE"])
         return env
 
diff --git a/tests/session/cmd/test_show_config.py b/tests/session/cmd/test_show_config.py
index f0acb3d794..ab71cbc557 100644
--- a/tests/session/cmd/test_show_config.py
+++ b/tests/session/cmd/test_show_config.py
@@ -115,10 +115,11 @@ def test_pass_env_config_default(tox_project: ToxProjectCreator, stdout_is_atty:
     pass_env = outcome.env_conf("py")["pass_env"]
     is_win = sys.platform == "win32"
     expected = (
-        (["COMSPEC"] if is_win else [])
+        ["CC", "CCSHARED"]
+        + (["COMSPEC"] if is_win else [])
         + ["CURL_CA_BUNDLE", "LANG", "LANGUAGE", "LD_LIBRARY_PATH"]
         + (["MSYSTEM", "NUMBER_OF_PROCESSORS", "PATHEXT"] if is_win else [])
-        + ["PIP_*", "PKG_CONFIG_PATH"]
+        + ["PIP_*", "PKG_CONFIG", "PKG_CONFIG_PATH", "PKG_CONFIG_SYSROOT_DIR"]
         + (["PROCESSOR_ARCHITECTURE"] if is_win else [])
         + (["PROGRAMDATA"] if is_win else [])
         + (["PROGRAMFILES"] if is_win else [])