diff --git a/tools/perf/util/setup.py b/tools/perf/util/setup.py
index 261a55e7e1b2..63f758c655d5 100644
--- a/tools/perf/util/setup.py
+++ b/tools/perf/util/setup.py
@@ -9,12 +9,14 @@ def clang_has_option(option):
 
 cc = getenv("CC")
 if cc == "clang":
-    from _sysconfigdata import build_time_vars
-    build_time_vars["CFLAGS"] = sub("-specs=[^ ]+", "", build_time_vars["CFLAGS"])
-    if not clang_has_option("-mcet"):
-        build_time_vars["CFLAGS"] = sub("-mcet", "", build_time_vars["CFLAGS"])
-    if not clang_has_option("-fcf-protection"):
-        build_time_vars["CFLAGS"] = sub("-fcf-protection", "", build_time_vars["CFLAGS"])
+    from distutils.sysconfig import get_config_vars
+    vars = get_config_vars()
+    for var in ('CFLAGS', 'OPT'):
+        vars[var] = sub("-specs=[^ ]+", "", vars[var])
+        if not clang_has_option("-mcet"):
+            vars[var] = sub("-mcet", "", vars[var])
+        if not clang_has_option("-fcf-protection"):
+            vars[var] = sub("-fcf-protection", "", vars[var])
 
 from distutils.core import setup, Extension