diff --git a/EOS/helmholtz/actual_eos.H b/EOS/helmholtz/actual_eos.H
index 737dc87ec9..b1719d5672 100644
--- a/EOS/helmholtz/actual_eos.H
+++ b/EOS/helmholtz/actual_eos.H
@@ -477,9 +477,9 @@ void apply_ions (T& state)
 {
     using namespace helmholtz;
 
-    const Real pi      = 3.1415926535897932384e0_rt;
-    const Real sioncon = (2.0e0_rt * pi * amu * kerg)/(h*h);
-    const Real kergavo = kerg * avo_eos;
+    constexpr Real pi      = 3.1415926535897932384e0_rt;
+    constexpr Real sioncon = (2.0e0_rt * pi * amu * kerg)/(h*h);
+    constexpr Real kergavo = kerg * avo_eos;
 
     Real deni = 1.0e0_rt / state.rho;
     Real tempi = 1.0e0_rt / state.T;
@@ -553,14 +553,14 @@ void apply_radiation (T& state)
 {
     using namespace helmholtz;
 
-    const Real clight  = 2.99792458e10_rt;
+    constexpr Real clight  = 2.99792458e10_rt;
 #ifdef RADIATION
-    const Real ssol    = 0.0e0_rt;
+    constexpr Real ssol    = 0.0e0_rt;
 #else
-    const Real ssol    = 5.67051e-5_rt;
+    constexpr Real ssol    = 5.67051e-5_rt;
 #endif
-    const Real asol    = 4.0e0_rt * ssol / clight;
-    const Real asoli3  = asol/3.0e0_rt;
+    constexpr Real asol    = 4.0e0_rt * ssol / clight;
+    constexpr Real asoli3  = asol/3.0e0_rt;
 
     Real deni = 1.0e0_rt / state.rho;
     Real tempi = 1.0e0_rt / state.T;
@@ -638,19 +638,19 @@ void apply_coulomb_corrections (T& state)
     using namespace helmholtz;
 
     // Constants used for the Coulomb corrections
-    const Real a1 = -0.898004e0_rt;
-    const Real b1 =  0.96786e0_rt;
-    const Real c1 =  0.220703e0_rt;
-    const Real d1 = -0.86097e0_rt;
-    const Real e1 =  2.5269e0_rt;
-    const Real a2 =  0.29561e0_rt;
-    const Real b2 =  1.9885e0_rt;
-    const Real c2 =  0.288675e0_rt;
-    const Real qe   = 4.8032042712e-10_rt;
-    const Real esqu = qe * qe;
-    const Real onethird = 1.0e0_rt/3.0e0_rt;
-    const Real forth = 4.0e0_rt/3.0e0_rt;
-    const Real pi    = 3.1415926535897932384e0_rt;
+    constexpr Real a1 = -0.898004e0_rt;
+    constexpr Real b1 =  0.96786e0_rt;
+    constexpr Real c1 =  0.220703e0_rt;
+    constexpr Real d1 = -0.86097e0_rt;
+    constexpr Real e1 =  2.5269e0_rt;
+    constexpr Real a2 =  0.29561e0_rt;
+    constexpr Real b2 =  1.9885e0_rt;
+    constexpr Real c2 =  0.288675e0_rt;
+    constexpr Real qe   = 4.8032042712e-10_rt;
+    constexpr Real esqu = qe * qe;
+    constexpr Real onethird = 1.0e0_rt/3.0e0_rt;
+    constexpr Real forth = 4.0e0_rt/3.0e0_rt;
+    constexpr Real pi    = 3.1415926535897932384e0_rt;
 
     [[maybe_unused]] Real pcoul    = 0.e0_rt;
     [[maybe_unused]] Real dpcouldd = 0.e0_rt;