diff --git a/dumux/material/fluidsystems/1p.hh b/dumux/material/fluidsystems/1p.hh
index ef7cf21f86439d7c807205ca0e88bf0cffb43afb..a997df1f1329d298c4df9b1a6ee9665c433adf8d 100644
--- a/dumux/material/fluidsystems/1p.hh
+++ b/dumux/material/fluidsystems/1p.hh
@@ -280,7 +280,7 @@ public:
         assert(0 <= compIdx  && compIdx < numComponents);
 
         if (phaseIdx == compIdx)
-            // TODO (?): calculate the real fugacity coefficient of
+            // We could calculate the real fugacity coefficient of
             // the component in the fluid. Probably that's not worth
             // the effort, since the fugacity coefficient of the other
             // component is infinite anyway...
diff --git a/dumux/material/fluidsystems/2pimmiscible.hh b/dumux/material/fluidsystems/2pimmiscible.hh
index dc0e751e2a3648aab7852cc1c5a9c8d85c130ffc..565c754895470daf1c252fbc5c8cd956f5d19f0f 100644
--- a/dumux/material/fluidsystems/2pimmiscible.hh
+++ b/dumux/material/fluidsystems/2pimmiscible.hh
@@ -319,7 +319,7 @@ public:
         assert(0 <= compIdx  && compIdx < numComponents);
 
         if (phaseIdx == compIdx)
-            // TODO (?): calculate the real fugacity coefficient of
+            // We could calculate the real fugacity coefficient of
             // the component in the fluid. Probably that's not worth
             // the effort, since the fugacity coefficient of the other
             // component is infinite anyway...
diff --git a/dumux/material/fluidsystems/brineair.hh b/dumux/material/fluidsystems/brineair.hh
index 922eba52d3f95396f71f231a03be006afeaaa91f..137bce6391c9ddd67d570d07aa8d45474f29b2c6 100644
--- a/dumux/material/fluidsystems/brineair.hh
+++ b/dumux/material/fluidsystems/brineair.hh
@@ -475,7 +475,6 @@ public:
                                        int phaseIdx,
                                        int compIdx)
     {
-        // TODO!
         DUNE_THROW(Dune::NotImplemented, "Diffusion coefficients");
     }
 
diff --git a/dumux/material/fluidsystems/brineco2.hh b/dumux/material/fluidsystems/brineco2.hh
index 097494961072ef4ec4ddb310cbc4098dcbde41bf..2a57d410ff8597034e5b6911c647dd22d5bb3c24 100644
--- a/dumux/material/fluidsystems/brineco2.hh
+++ b/dumux/material/fluidsystems/brineco2.hh
@@ -457,7 +457,6 @@ public:
                                        int phaseIdx,
                                        int compIdx)
     {
-        // TODO!
         DUNE_THROW(Dune::NotImplemented, "Diffusion coefficients");
     }
 
diff --git a/dumux/material/fluidsystems/h2on2liquidphase.hh b/dumux/material/fluidsystems/h2on2liquidphase.hh
index 7258be6e110d4772e2497b0e0f184caf8e3ef3d0..f8644df6621d6c4a1133f24b7f9d97b3fafa63c4 100644
--- a/dumux/material/fluidsystems/h2on2liquidphase.hh
+++ b/dumux/material/fluidsystems/h2on2liquidphase.hh
@@ -474,7 +474,6 @@ public:
                                        int phaseIdx,
                                        int compIdx)
     {
-        // TODO!
         DUNE_THROW(Dune::NotImplemented, "Diffusion coefficients");
     }
 
diff --git a/dumux/material/fluidsystems/purewatersimple.hh b/dumux/material/fluidsystems/purewatersimple.hh
index 645289e03390f640ca6c6f6c4e23eb1873661ad4..4d128335a082e3ee0145996d3d3c16c8a70d7ada 100644
--- a/dumux/material/fluidsystems/purewatersimple.hh
+++ b/dumux/material/fluidsystems/purewatersimple.hh
@@ -455,7 +455,6 @@ public:
                                        int phaseIdx,
                                        int compIdx)
     {
-        // TODO!
         DUNE_THROW(Dune::NotImplemented, "Diffusion coefficients");
     }