diff --git a/opm/material/common/PolynomialUtils.hpp b/opm/material/common/PolynomialUtils.hpp
index ebf7c49de..5abfdc972 100644
--- a/opm/material/common/PolynomialUtils.hpp
+++ b/opm/material/common/PolynomialUtils.hpp
@@ -369,7 +369,7 @@ unsigned cubicRoots(SolContainer* sol,
 
         // Find one real root of a depressed cubic using hyperbolic method. Different solutions depending on 
         // sign of p
-        Scalar t;
+        Scalar t = 0;
         if (p < 0) {
             // Help calculation
             Scalar theta = (1.0 / 3.0) * acosh( ((-3.0 * abs(q)) / (2.0 * p)) * sqrt(-3.0 / p) );
diff --git a/opm/material/fluidsystems/Co2BrineFluidSystem.hh b/opm/material/fluidsystems/Co2BrineFluidSystem.hh
index 11d13fb00..1c8498cc6 100644
--- a/opm/material/fluidsystems/Co2BrineFluidSystem.hh
+++ b/opm/material/fluidsystems/Co2BrineFluidSystem.hh
@@ -177,8 +177,8 @@ namespace Opm {
                                            unsigned phaseIdx,
                                            unsigned compIdx)
         {
-            assert(0 <= phaseIdx && phaseIdx < numPhases);
-            assert(0 <= compIdx && compIdx < numComponents);
+            assert(phaseIdx < numPhases);
+            assert(compIdx < numComponents);
 
             LhsEval phi = PengRobinsonMixture::computeFugacityCoefficient(fluidState, paramCache, phaseIdx, compIdx);
 
diff --git a/opm/material/fluidsystems/ThreeComponentFluidSystem.hh b/opm/material/fluidsystems/ThreeComponentFluidSystem.hh
index 952573974..5497e2209 100644
--- a/opm/material/fluidsystems/ThreeComponentFluidSystem.hh
+++ b/opm/material/fluidsystems/ThreeComponentFluidSystem.hh
@@ -182,8 +182,8 @@ namespace Opm {
                                            unsigned phaseIdx,
                                            unsigned compIdx)
         {
-            assert(0 <= phaseIdx && phaseIdx < numPhases);
-            assert(0 <= compIdx && compIdx < numComponents);
+            assert(phaseIdx < numPhases);
+            assert(compIdx < numComponents);
 
             // TODO: here the derivatives for the phi are dropped. Should we keep the derivatives against the pressure
             // and temperature?