diff --git a/src/HLLC.hpp b/src/HLLC.hpp
index fc7c37e3b..25fb236a9 100644
--- a/src/HLLC.hpp
+++ b/src/HLLC.hpp
@@ -36,10 +36,10 @@ AMREX_FORCE_INLINE AMREX_GPU_DEVICE auto HLLC(quokka::HydroState<N_scalars> cons
 	double cs_tilde = NAN;
 	if (gamma != 1.0) {
 		// TODO(ben): implement Roe average for general EOS
-		const double C_star_P = 1.0 / (gamma - 1.0);
-		const double C_star_rho = 0.0;
+		const double C_tilde_P = 1.0 / (gamma - 1.0);
+		const double C_tilde_rho = 0.0;
 		// equation 4.12 of Kershaw+1998
-		cs_tilde = std::sqrt((1.0 / C_star_P) * (H_tilde - 0.5 * vsq_tilde - C_star_rho));
+		cs_tilde = std::sqrt((1.0 / C_tilde_P) * (H_tilde - 0.5 * vsq_tilde - C_tilde_rho));
 	} else {
 		cs_tilde = 0.5 * (sL.cs + sR.cs);
 	}