diff --git a/.Rbuildignore b/.Rbuildignore
index b2e6b5b..dd34f11 100644
--- a/.Rbuildignore
+++ b/.Rbuildignore
@@ -6,3 +6,4 @@
 ^pkgdown$
 .github
 ^\.github$
+^cran-comments\.md$
diff --git a/cran-comments.md b/cran-comments.md
new file mode 100644
index 0000000..1a00d5f
--- /dev/null
+++ b/cran-comments.md
@@ -0,0 +1,18 @@
+## Initial release
+
+This package implements a method that builds the coefficients of a polynomial
+model that performs almost equivalently as a given MLP neural network.
+
+## Test environments
+
+- macOS-latest, windows-latest, ubuntu-latest (on GA), R devel, release, oldrel
+- win-builder, R devel
+
+## R CMD check results
+
+There is one NOTE:
+
+> checking C++ specification ... NOTE
+    Specified C++14: please drop specification unless essential
+
+which is essential.
diff --git a/man/add_constraints.Rd b/man/add_constraints.Rd
index e165348..7a1a5b0 100644
--- a/man/add_constraints.Rd
+++ b/man/add_constraints.Rd
@@ -33,6 +33,7 @@ helper in order to have a sequential model in the appropriate form.
 }
 \examples{
 \dontrun{
+if (requireNamespace("keras", quietly=TRUE)) {
   # ---- Example with a keras/tensorflow network ----
   # Build a small nn:
   nn <- keras::keras_model_sequential()
@@ -45,6 +46,7 @@ helper in order to have a sequential model in the appropriate form.
   # Check that class of the constrained nn is "nn2poly"
   class(nn_constrained)[1]
 }
+}
 
 if (requireNamespace("luz", quietly=TRUE)) {
   # ---- Example with a luz/torch network ----