diff --git a/compiler/cpp/src/generate/t_cpp_generator.cc b/compiler/cpp/src/generate/t_cpp_generator.cc
index d85f06f..550e519 100644
--- a/compiler/cpp/src/generate/t_cpp_generator.cc
+++ b/compiler/cpp/src/generate/t_cpp_generator.cc
@@ -823,7 +823,7 @@
         tstruct->get_ascii_fingerprint() << "\";" << endl <<
       indent() << stat << "const uint8_t " << nspace <<
         "binary_fingerprint[" << t_type::fingerprint_len << "]" << comment << "= {";
-    char* comma = "";
+    const char* comma = "";
     for (int i = 0; i < t_type::fingerprint_len; i++) {
       out << comma << "0x" << t_struct::byte_to_hex(tstruct->get_binary_fingerprint()[i]);
       comma = ",";