diff --git a/config/rules.mk b/config/rules.mk
index 343f7843d123..352a9663cf9d 100644
--- a/config/rules.mk
+++ b/config/rules.mk
@@ -702,7 +702,7 @@ define syms_template
 syms:: $(2)
 $(2): $(1)
 ifdef MOZ_CRASHREPORTER
-	$$(call py_action,dumpsymbols,$$(abspath $$<) $$(abspath $$@) $$(DUMP_SYMBOLS_FLAGS))
+	$$(call py3_action,dumpsymbols,$$(abspath $$<) $$(abspath $$@) $$(DUMP_SYMBOLS_FLAGS))
 endif
 endef
 
diff --git a/python/mozbuild/mozbuild/action/dumpsymbols.py b/python/mozbuild/mozbuild/action/dumpsymbols.py
index 186db22861c4..db37cea2a6b4 100644
--- a/python/mozbuild/mozbuild/action/dumpsymbols.py
+++ b/python/mozbuild/mozbuild/action/dumpsymbols.py
@@ -80,8 +80,8 @@ def dump_symbols(target, tracking_file, count_ctors=False):
     if count_ctors:
         args.append('--count-ctors')
     print('Running: %s' % ' '.join(args))
-    out_files = subprocess.check_output(args)
-    with open(tracking_file, 'w') as fh:
+    out_files = subprocess.check_output(args, universal_newlines=True)
+    with open(tracking_file, 'w', encoding='utf-8', newline='\n') as fh:
         fh.write(out_files)
         fh.flush()