diff --git a/toolchain/mac/BUILD.gn b/toolchain/mac/BUILD.gn
index ba3f48c86..c43049cd8 100644
--- a/toolchain/mac/BUILD.gn
+++ b/toolchain/mac/BUILD.gn
@@ -29,7 +29,7 @@ ld = cxx
 # file of the win tool.
 gyp_mac_tool_source =
   rebase_path("//tools/gyp/pylib/gyp/mac_tool.py", root_build_dir)
-exec_script("setup_toolchain.py", [ gyp_mac_tool_source ], "value")
+exec_script("setup_toolchain.py", [ gyp_mac_tool_source ])
 
 # Shared toolchain definition. Invocations should set toolchain_os to set the
 # build args in this definition.
diff --git a/toolchain/win/BUILD.gn b/toolchain/win/BUILD.gn
index 143aa0a0e..3006d5bdb 100644
--- a/toolchain/win/BUILD.gn
+++ b/toolchain/win/BUILD.gn
@@ -16,8 +16,7 @@ assert(is_win)
 gyp_win_tool_path = rebase_path("//tools/gyp/pylib/gyp/win_tool.py",
                                 root_build_dir)
 exec_script("setup_toolchain.py",
-            [ visual_studio_path, gyp_win_tool_path, windows_sdk_path ],
-            "string")
+            [ visual_studio_path, gyp_win_tool_path, windows_sdk_path ])
 
 stamp_command = "$python_path gyp-win-tool stamp \$out"
 copy_command = "$python_path gyp-win-tool recursive-mirror \$in \$out"