diff --git a/.cirrus.yml b/.cirrus.yml
index 37bb92e759..6b4f27ee2a 100644
--- a/.cirrus.yml
+++ b/.cirrus.yml
@@ -219,7 +219,7 @@ alpine_task:
 # We aim to support both the current and previous macOS release.
 macos_big_sur_task:
   macos_instance:
-    image: big-sur-base
+    image: big-sur-xcode-12.5
   prepare_script: ./ci/macos/prepare.sh
   << : *CI_TEMPLATE
   << : *MACOS_RESOURCES_TEMPLATE
diff --git a/CHANGES b/CHANGES
index 6ea0cfeffd..8063a996d9 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,13 @@
+4.1.0-dev.715 | 2021-06-09 09:12:26 -0700
+
+  * Fix macOS Big Sur builds on Cirrus
+
+    - Upgrade the Big Sur VM to use the Xcode 12.5 version. This has a newer
+      version of brew installed on it that fixes an issue with an EOL package host
+      that finally shut down for good recently.
+    - Use 'brew upgrade' for openssl and cmake, since those are both present on the
+      base VM. This prevents 'brew install' from printing an error if the package
+      exists but is out of date. (Tim Wojtulewicz, Corelight)
 
 4.1.0-dev.713 | 2021-06-08 13:54:28 -0700
 
diff --git a/VERSION b/VERSION
index f2c9ae943a..d0fde79737 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-4.1.0-dev.713
+4.1.0-dev.715
diff --git a/ci/macos/prepare.sh b/ci/macos/prepare.sh
index e12bab11a5..2e81e060c3 100755
--- a/ci/macos/prepare.sh
+++ b/ci/macos/prepare.sh
@@ -5,4 +5,5 @@ sysctl hw.model hw.machine hw.ncpu hw.physicalcpu hw.logicalcpu
 set -e
 set -x
 
-brew install cmake swig openssl bison
+brew upgrade cmake openssl
+brew install swig bison