diff --git a/src/bisection-simpler-example.cc b/src/bisection-simpler-example.cc
index ddc1fbfaf218d64d5bfbe2baca369a75c9d519fc..b8466adc22ab4d80e5032b452328baa974cc513d 100644
--- a/src/bisection-simpler-example.cc
+++ b/src/bisection-simpler-example.cc
@@ -31,7 +31,7 @@ class SampleFunctional : public SmallFunctional<2> {
     return y;
   }
 
-  SmallMatrix d2(const SmallVector v) const { return A_; }
+  SmallMatrix d2(const SmallVector) const { return A_; }
 
 private:
   SmallMatrix A_;
diff --git a/src/bisection-simpler-example2-gradient.cc b/src/bisection-simpler-example2-gradient.cc
index 2adcea7874ea74ee2cdcae2c6dad31f089f1186c..14d702165f2a0018ac90d16d512600ccf9249d36 100644
--- a/src/bisection-simpler-example2-gradient.cc
+++ b/src/bisection-simpler-example2-gradient.cc
@@ -37,7 +37,7 @@ class SampleFunctional : public SmallFunctional<dimension> {
     return y;
   }
 
-  SmallMatrix d2(const SmallVector v) const { return A_; }
+  SmallMatrix d2(const SmallVector) const { return A_; }
 
   // extending the interface here
   double directionalDerivative(const SmallVector x,
diff --git a/src/bisection-simpler-example2.cc b/src/bisection-simpler-example2.cc
index f74e889dbd1ad7138a7bd64d88eaa36c27695603..a34baf5d2635663990da3aba88cfcc847cc23106 100644
--- a/src/bisection-simpler-example2.cc
+++ b/src/bisection-simpler-example2.cc
@@ -35,7 +35,7 @@ class SampleFunctional : public SmallFunctional<dimension> {
     return y;
   }
 
-  SmallMatrix d2(const SmallVector v) const { return A_; }
+  SmallMatrix d2(const SmallVector) const { return A_; }
 
 private:
   SmallMatrix A_;