diff --git a/gtsam/linear/GaussianBayesNet.cpp b/gtsam/linear/GaussianBayesNet.cpp
index bc96452b9..e9938ceb6 100644
--- a/gtsam/linear/GaussianBayesNet.cpp
+++ b/gtsam/linear/GaussianBayesNet.cpp
@@ -187,16 +187,16 @@ namespace gtsam {
   }
 
   /* ************************************************************************* */
-  double GaussianBayesNet::logDeterminant() const
-  {
+  double GaussianBayesNet::logDeterminant() const {
     double logDet = 0.0;
-    for(const sharedConditional& cg: *this) {
-      if(cg->get_model()) {
+    for (const sharedConditional& cg : *this) {
+      if (cg->get_model()) {
         Vector diag = cg->R().diagonal();
         cg->get_model()->whitenInPlace(diag);
-        logDet += diag.unaryExpr(ptr_fun<double,double>(log)).sum();
+        logDet += diag.unaryExpr([](double x) { return log(x); }).sum();
       } else {
-        logDet += cg->R().diagonal().unaryExpr(ptr_fun<double,double>(log)).sum();
+        logDet +=
+            cg->R().diagonal().unaryExpr([](double x) { return log(x); }).sum();
       }
     }
     return logDet;
diff --git a/gtsam/linear/GaussianBayesTree.cpp b/gtsam/linear/GaussianBayesTree.cpp
index 8d0fafb61..13c19bce6 100644
--- a/gtsam/linear/GaussianBayesTree.cpp
+++ b/gtsam/linear/GaussianBayesTree.cpp
@@ -40,11 +40,11 @@ namespace gtsam {
     parentSum += clique->conditional()
                      ->R()
                      .diagonal()
-                     .unaryExpr(std::ptr_fun<double, double>(log))
+                     .unaryExpr([](double x) { return log(x); })
                      .sum();
     return 0;
   }
-  }
+  }  // namespace internal
 
   /* ************************************************************************* */
   bool GaussianBayesTree::equals(const This& other, double tol) const