diff --git a/.circleci/config.yml b/.circleci/config.yml
index 621b11ba3..e601db0bc 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -80,7 +80,7 @@ jobs:
 
   cargo-build-osx:
     macos:
-      xcode: "9.4.1"
+      xcode: 12.5.0
     environment:
       GRADLE_OPTS: -Dorg.gradle.console=plain -Dorg.gradle.internal.launcher.welcomeMessageEnabled=false
       FL_OUTPUT_DIR: output
diff --git a/changelog/@unreleased/pr-506.v2.yml b/changelog/@unreleased/pr-506.v2.yml
new file mode 100644
index 000000000..81a08c5b2
--- /dev/null
+++ b/changelog/@unreleased/pr-506.v2.yml
@@ -0,0 +1,5 @@
+type: improvement
+improvement:
+  description: Upgrade Xcode version to 12.5.0
+  links:
+  - https://github.com/palantir/conjure-verification/pull/506