diff --git a/src/libraries/JANA/Utils/JTablePrinter.cc b/src/libraries/JANA/Utils/JTablePrinter.cc
index 61494c60b..b797d7062 100644
--- a/src/libraries/JANA/Utils/JTablePrinter.cc
+++ b/src/libraries/JANA/Utils/JTablePrinter.cc
@@ -215,7 +215,7 @@ void JTablePrinter::Render(std::ostream& os) {
     }
 }
 
-std::ostream& operator<<(std::ostream& os, JTablePrinter& t) {
+std::ostream& operator<<(std::ostream& os, const JTablePrinter& t) {
     t.Render(os);
     return os;
 }
diff --git a/src/libraries/JANA/Utils/JTablePrinter.h b/src/libraries/JANA/Utils/JTablePrinter.h
index 969109c2f..cf9d50fd7 100644
--- a/src/libraries/JANA/Utils/JTablePrinter.h
+++ b/src/libraries/JANA/Utils/JTablePrinter.h
@@ -52,7 +52,7 @@ class JTablePrinter {
 
 };
 
-std::ostream& operator<<(std::ostream& os, JTablePrinter& t);
+std::ostream& operator<<(std::ostream& os, const JTablePrinter& t);
 
 template <typename T>
 JTablePrinter& JTablePrinter::operator|(T cell) {