diff --git a/src/time_zone_format.cc b/src/time_zone_format.cc
index 71e2381..cea6be3 100644
--- a/src/time_zone_format.cc
+++ b/src/time_zone_format.cc
@@ -974,7 +974,7 @@ bool parse(const std::string& format, const std::string& input,
   while (std::isspace(*data)) ++data;
 
   // parse() must consume the entire input string.
-  if (*data != '\0') {
+  if (data != input.data() + input.size()) {
     if (err != nullptr) *err = "Illegal trailing data in input string";
     return false;
   }
diff --git a/src/time_zone_format_test.cc b/src/time_zone_format_test.cc
index f2d2b8b..c25b5e3 100644
--- a/src/time_zone_format_test.cc
+++ b/src/time_zone_format_test.cc
@@ -896,6 +896,9 @@ TEST(Parse, ErrorCases) {
   EXPECT_FALSE(parse("%Ez", "+-0:00", tz, &tp));
   EXPECT_FALSE(parse("%z", "-00-0", tz, &tp));
   EXPECT_FALSE(parse("%Ez", "-00:-0", tz, &tp));
+
+  // Check that we do not accept strings with embedded NULs.
+  EXPECT_FALSE(parse("%Y", std::string("2026\0payload", 12), tz, &tp));
 }
 
 TEST(Parse, PosixConversions) {