diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index bd3f639..8c3ab1d 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -24,22 +24,22 @@ jobs:
         include:
           - toolset: gcc-4.7
             cxxstd: "03,11"
-            os: ubuntu-16.04
+            os: ubuntu-18.04
             install: g++-4.7
           - toolset: gcc-4.8
             cxxstd: "03,11"
-            os: ubuntu-16.04
+            os: ubuntu-18.04
             install: g++-4.8
           - toolset: gcc-4.9
             cxxstd: "03,11"
-            os: ubuntu-16.04
+            os: ubuntu-18.04
             install: g++-4.9
           - toolset: gcc-5
             cxxstd: "03,11,14,1z"
-            os: ubuntu-16.04
+            os: ubuntu-18.04
           - toolset: gcc-6
             cxxstd: "03,11,14,1z"
-            os: ubuntu-16.04
+            os: ubuntu-18.04
             install: g++-6
           - toolset: gcc-7
             cxxstd: "03,11,14,17"
@@ -61,37 +61,37 @@ jobs:
           - toolset: clang
             compiler: clang++-3.5
             cxxstd: "03,11"
-            os: ubuntu-16.04
+            os: ubuntu-18.04
             install: clang-3.5
           - toolset: clang
             compiler: clang++-3.6
             cxxstd: "03,11,14"
-            os: ubuntu-16.04
+            os: ubuntu-18.04
             install: clang-3.6
           - toolset: clang
             compiler: clang++-3.7
             cxxstd: "03,11,14"
-            os: ubuntu-16.04
+            os: ubuntu-18.04
             install: clang-3.7
           - toolset: clang
             compiler: clang++-3.8
             cxxstd: "03,11,14"
-            os: ubuntu-16.04
+            os: ubuntu-18.04
             install: clang-3.8
           - toolset: clang
             compiler: clang++-3.9
             cxxstd: "03,11,14"
-            os: ubuntu-16.04
+            os: ubuntu-18.04
             install: clang-3.9
           - toolset: clang
             compiler: clang++-4.0
             cxxstd: "03,11,14"
-            os: ubuntu-16.04
+            os: ubuntu-18.04
             install: clang-4.0
           - toolset: clang
             compiler: clang++-5.0
             cxxstd: "03,11,14,1z"
-            os: ubuntu-16.04
+            os: ubuntu-18.04
             install: clang-5.0
           - toolset: clang
             compiler: clang++-6.0