diff --git a/.github/workflows/compatibility_tests.yml b/.github/workflows/compatibility_tests.yml
index 060c4b52..7ce4a137 100644
--- a/.github/workflows/compatibility_tests.yml
+++ b/.github/workflows/compatibility_tests.yml
@@ -14,7 +14,7 @@ jobs:
       matrix:
         include:
           - os: macos-15
-            xcode-version: "16.3"   # Swift 6.1
+            xcode-version: "16.4"   # Swift 6.1.2
     runs-on: ${{ matrix.os }}
     env:
       OPENGRAPH_WERROR: 1
diff --git a/.github/workflows/ios.yml b/.github/workflows/ios.yml
index 30a80ba9..7cf09d49 100644
--- a/.github/workflows/ios.yml
+++ b/.github/workflows/ios.yml
@@ -13,10 +13,10 @@ jobs:
       fail-fast: false
       matrix:
         os: [macos-15]
-        xcode-version: ["16.3"]   # Swift 6.1
-        ios-version: ["18.0"]
+        xcode-version: ["16.4"]   # Swift 6.1.2
+        ios-version: ["18.5"]
         include:
-          - ios-version: "18.0"
+          - ios-version: "18.5"
             ios-simulator-name: "iPhone 16 Pro"
     runs-on: ${{ matrix.os }}
     env:
diff --git a/.github/workflows/macos.yml b/.github/workflows/macos.yml
index 5eafe098..194c1d6c 100644
--- a/.github/workflows/macos.yml
+++ b/.github/workflows/macos.yml
@@ -13,7 +13,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [macos-15]
-        xcode-version: ["16.3"]   # Swift 6.1
+        xcode-version: ["16.4"]   # Swift 6.1.2
     runs-on: ${{ matrix.os }}
     env:
       OPENGRAPH_WERROR: 1
diff --git a/.github/workflows/ubuntu.yml b/.github/workflows/ubuntu.yml
index 7915536c..8ba54b26 100644
--- a/.github/workflows/ubuntu.yml
+++ b/.github/workflows/ubuntu.yml
@@ -12,7 +12,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        swift_version: ["6.1"]
+        swift_version: ["6.1.2"]
     runs-on: ubuntu-22.04
     env:
       OPENGRAPH_WERROR: 1
diff --git a/README.md b/README.md
index d2e0dc53..e602a902 100644
--- a/README.md
+++ b/README.md
@@ -27,7 +27,7 @@ Currently, this project is in early development.
 
 ## Build
 
-The current suggested toolchain to build the project is Swift 6.1 / Xcode 16.3.
+The current suggested toolchain to build the project is Swift 6.1.2 / Xcode 16.4.
 
 ## License