diff --git a/src/lib_json/json_reader.cpp b/src/lib_json/json_reader.cpp
index 23cbe60..19922a8 100644
--- a/src/lib_json/json_reader.cpp
+++ b/src/lib_json/json_reader.cpp
@@ -1175,8 +1175,11 @@ bool OurReader::readToken(Token& token) {
     if (features_.allowSingleQuotes_) {
       token.type_ = tokenString;
       ok = readStringSingleQuote();
-      break;
-    } // else fall through
+    } else {
+      // If we don't allow single quotes, this is a failure case.
+      ok = false;
+    }
+    break;
   case '/':
     token.type_ = tokenComment;
     ok = readComment();
diff --git a/test/data/fail_invalid_quote.json b/test/data/fail_invalid_quote.json
new file mode 100644
index 0000000..dae27f5
--- /dev/null
+++ b/test/data/fail_invalid_quote.json
@@ -0,0 +1 @@
+{'//this is bad JSON.'}
\ No newline at end of file