diff --git a/bolt/test/lit.site.cfg.py.in b/bolt/test/lit.site.cfg.py.in
--- a/bolt/test/lit.site.cfg.py.in
+++ b/bolt/test/lit.site.cfg.py.in
@@ -9,7 +9,6 @@
 config.llvm_tools_dir = lit_config.substitute("@LLVM_TOOLS_DIR@")
 config.llvm_libs_dir = lit_config.substitute("@LLVM_LIBS_DIR@")
 config.llvm_shlib_dir = lit_config.substitute("@SHLIBDIR@")
-config.llvm_plugin_ext = "@LLVM_PLUGIN_EXT@"
 config.lit_tools_dir = "@LLVM_LIT_TOOLS_DIR@"
 config.host_triple = "@LLVM_HOST_TRIPLE@"
 config.target_triple = "@LLVM_TARGET_TRIPLE@"
diff --git a/llvm/utils/gn/secondary/bolt/test/BUILD.gn b/llvm/utils/gn/secondary/bolt/test/BUILD.gn
--- a/llvm/utils/gn/secondary/bolt/test/BUILD.gn
+++ b/llvm/utils/gn/secondary/bolt/test/BUILD.gn
@@ -55,14 +55,6 @@
   } else {
     assert(false, "unimplemented host_cpu " + host_cpu)
   }
-
-  if (host_os == "mac") {
-    extra_values += [ "LLVM_PLUGIN_EXT=.dylib" ]
-  } else if (host_os == "win") {
-    extra_values += [ "LLVM_PLUGIN_EXT=.dll" ]
-  } else {
-    extra_values += [ "LLVM_PLUGIN_EXT=.so" ]
-  }
 }
 
 write_lit_config("lit_unit_site_cfg") {