diff --git a/src/BroString.cc b/src/BroString.cc
index c86e14cf37..3dca28439c 100644
--- a/src/BroString.cc
+++ b/src/BroString.cc
@@ -166,17 +166,19 @@ void BroString::Set(const BroString& str)
 
 const char* BroString::CheckString() const
 	{
+	void *nulTerm;
 	if ( n == 0 )
 		return "";
 
-	if ( memchr(b, '\0', n + final_NUL) != &b[n] )
+	nulTerm = memchr(b, '\0', n + final_NUL);
+	if ( nulTerm != &b[n] )
 		{
 		// Either an embedded NUL, or no final NUL.
 		char* exp_s = Render();
-		if ( b[n-1] != '\0' )
-			reporter->Error("string without NUL terminator: \"%s\"", exp_s);
-		else
+		if ( nulTerm )
 			reporter->Error("string with embedded NUL: \"%s\"", exp_s);
+		else
+			reporter->Error("string without NUL terminator: \"%s\"", exp_s);
 
 		delete [] exp_s;
 		return "<string-with-NUL>";
diff --git a/testing/btest/Baseline/core.embedded-null/.stdout b/testing/btest/Baseline/core.embedded-null/.stdout
new file mode 100644
index 0000000000..edf309beb0
--- /dev/null
+++ b/testing/btest/Baseline/core.embedded-null/.stdout
@@ -0,0 +1 @@
+error: string with embedded NUL: "hi\x00there"
diff --git a/testing/btest/core/embedded-null.bro b/testing/btest/core/embedded-null.bro
new file mode 100644
index 0000000000..95a4c965a9
--- /dev/null
+++ b/testing/btest/core/embedded-null.bro
@@ -0,0 +1,8 @@
+# @TEST-EXEC: bro -b %INPUT 2>&1
+# @TEST-EXEC: btest-diff .stdout
+
+event bro_init()
+	{
+	local a = "hi\x00there";
+	unique_id(a);
+	}