diff --git a/.github/workflows/build-osal-documentation.yml b/.github/workflows/build-osal-documentation.yml
index 84f65eb06..365401f95 100644
--- a/.github/workflows/build-osal-documentation.yml
+++ b/.github/workflows/build-osal-documentation.yml
@@ -24,7 +24,7 @@ jobs:
     #Continue if check-for-duplicates found no duplicates. Always runs for pull-requests.
     needs: check-for-duplicates
     if: ${{ needs.check-for-duplicates.outputs.should_skip != 'true' }}
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-20.04
     timeout-minutes: 15
 
     steps:
@@ -65,4 +65,4 @@ jobs:
           if [[ -s osal-apiguide-warnings.log ]]; then
             cat osal-apiguide-warnings.log
             exit -1
-          fi
\ No newline at end of file
+          fi
diff --git a/.github/workflows/local_unit_test.yml b/.github/workflows/local_unit_test.yml
index e82f04cec..8597e13d8 100644
--- a/.github/workflows/local_unit_test.yml
+++ b/.github/workflows/local_unit_test.yml
@@ -22,7 +22,7 @@ jobs:
   Local-Unit-Test:
     needs: check-for-duplicates
     if: ${{ needs.check-for-duplicates.outputs.should_skip != 'true' }}
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-20.04
     timeout-minutes: 15
 
     steps:
diff --git a/CHANGELOG.md b/CHANGELOG.md
index e77e9b351..a136f13f9 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Changelog
 
+## Development Build: v6.0.0-rc4+dev165
+- Update CI to use Ubuntu 20.04
+- See <https://github.com/nasa/osal/pull/1334>
+
 ## Development Build: v6.0.0-rc4+dev161
 - Truncate symbol name if > OS_MAX_SYM_LEN
 - always provide UT stub library
diff --git a/src/os/inc/osapi-version.h b/src/os/inc/osapi-version.h
index ba46539da..0e662d0b8 100644
--- a/src/os/inc/osapi-version.h
+++ b/src/os/inc/osapi-version.h
@@ -34,7 +34,7 @@
 /*
  * Development Build Macro Definitions
  */
-#define OS_BUILD_NUMBER   161
+#define OS_BUILD_NUMBER   165
 #define OS_BUILD_BASELINE "v6.0.0-rc4"
 
 /*