diff --git a/.Rbuildignore b/.Rbuildignore
index c1c1347..6adbc05 100644
--- a/.Rbuildignore
+++ b/.Rbuildignore
@@ -13,3 +13,4 @@
 ^.*\.Rproj$
 ^\.Rproj\.user$
 ^\.travis\.yml$
+^\.github$
diff --git a/.github/.gitignore b/.github/.gitignore
new file mode 100644
index 0000000..2d19fc7
--- /dev/null
+++ b/.github/.gitignore
@@ -0,0 +1 @@
+*.html
diff --git a/.github/workflows/check-full.yaml b/.github/workflows/check-full.yaml
new file mode 100644
index 0000000..6faae3f
--- /dev/null
+++ b/.github/workflows/check-full.yaml
@@ -0,0 +1,58 @@
+# Workflow derived from https://github.com/r-lib/actions/tree/master/examples
+# Need help debugging build failures? Start at https://github.com/r-lib/actions#where-to-find-help
+#
+# NOTE: This workflow is overkill for most R packages and
+# check-standard.yaml is likely a better choice.
+# usethis::use_github_action("check-standard") will install it.
+on:
+  push:
+    branches: [main, master]
+  pull_request:
+    branches: [main, master]
+
+name: R-CMD-check
+
+jobs:
+  R-CMD-check:
+    runs-on: ${{ matrix.config.os }}
+
+    name: ${{ matrix.config.os }} (${{ matrix.config.r }})
+
+    strategy:
+      fail-fast: false
+      matrix:
+        config:
+          - {os: macOS-latest,   r: 'release'}
+
+          - {os: windows-latest, r: 'release'}
+          # Use 3.6 to trigger usage of RTools35
+          - {os: windows-latest, r: '3.6'}
+
+          # Use older ubuntu to maximise backward compatibility
+          - {os: ubuntu-18.04,   r: 'devel', http-user-agent: 'release'}
+          - {os: ubuntu-18.04,   r: 'release'}
+          - {os: ubuntu-18.04,   r: 'oldrel-1'}
+          - {os: ubuntu-18.04,   r: 'oldrel-2'}
+          - {os: ubuntu-18.04,   r: 'oldrel-3'}
+          - {os: ubuntu-18.04,   r: 'oldrel-4'}
+
+    env:
+      GITHUB_PAT: ${{ secrets.GITHUB_TOKEN }}
+      R_KEEP_PKG_SOURCE: yes
+
+    steps:
+      - uses: actions/checkout@v2
+
+      - uses: r-lib/actions/setup-pandoc@v1
+
+      - uses: r-lib/actions/setup-r@v1
+        with:
+          r-version: ${{ matrix.config.r }}
+          http-user-agent: ${{ matrix.config.http-user-agent }}
+          use-public-rspm: true
+
+      - uses: r-lib/actions/setup-r-dependencies@v1
+        with:
+          extra-packages: rcmdcheck
+
+      - uses: r-lib/actions/check-r-package@v1
diff --git a/README.md b/README.md
index 07ff957..752bd33 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,4 @@
-[![Travis-CI Build Status](https://travis-ci.org/nlmixrdevelopment/PreciseSums.svg?branch=master)](https://travis-ci.org/nlmixrdevelopment/PreciseSums)
-[![AppVeyor Build Status](https://ci.appveyor.com/api/projects/status/github/mattfidler/PreciseSums?branch=master&svg=true)](https://ci.appveyor.com/project/mattfidler/PreciseSums)
+  [![R-CMD-check](https://github.com/nlmixr2/PreciseSums/workflows/R-CMD-check/badge.svg)](https://github.com/nlmixr2/PreciseSums/actions)
 [![CRAN version](http://www.r-pkg.org/badges/version/PreciseSums)](https://cran.r-project.org/package=PreciseSums)
 
 This brings a few algorithms for precise sums and products to R.  They
diff --git a/src/prod.c b/src/prod.c
index 722ad18..2fd689c 100644
--- a/src/prod.c
+++ b/src/prod.c
@@ -12,7 +12,7 @@ extern double PreciseSums_pairwise_add_DOUBLE(double *a, int n);
 double PreciseSums_safe_log(double x){
   if (x <= 0){
     // Warning?
-    return log(DOUBLE_EPS);
+    return log(DBL_EPSILON);
   } else {
     return log(x);
   }