diff --git a/re2/re2.cc b/re2/re2.cc
index b9e44fc..fb43abf 100644
--- a/re2/re2.cc
+++ b/re2/re2.cc
@@ -56,8 +56,8 @@ RE2::Options::Options()
 
 RE2::Options::Options(RE2::CannedOptions opt)
   : encoding_(opt == RE2::Latin1 ? EncodingLatin1 : EncodingUTF8),
-    posix_syntax_(opt == RE2::POSIX),
-    longest_match_(opt == RE2::POSIX),
+    posix_syntax_(opt == RE2::POSIX_SYNTAX),
+    longest_match_(opt == RE2::POSIX_SYNTAX),
     log_errors_(opt != RE2::Quiet),
     max_mem_(kDefaultMaxMem),
     literal_(false),
diff --git a/re2/re2.h b/re2/re2.h
index c509853..98b06b8 100644
--- a/re2/re2.h
+++ b/re2/re2.h
@@ -251,7 +251,7 @@ class RE2 {
   enum CannedOptions {
     DefaultOptions = 0,
     Latin1, // treat input as Latin-1 (default UTF-8)
-    POSIX, // POSIX syntax, leftmost-longest match
+    POSIX_SYNTAX, // POSIX syntax, leftmost-longest match
     Quiet // do not log about regexp parse errors
   };