diff --git a/ports/string-theory/portfile.cmake b/ports/string-theory/portfile.cmake
index 6cf306ad68..fc76154027 100644
--- a/ports/string-theory/portfile.cmake
+++ b/ports/string-theory/portfile.cmake
@@ -2,7 +2,7 @@ vcpkg_from_github(
     OUT_SOURCE_PATH SOURCE_PATH
     REPO zrax/string_theory
     REF "${VERSION}"
-    SHA512 5071fb091dd5b5279776c2949b2bff7033c6bce336b1b4916e04957228884104b07e64ff3aa248b6498889fd50947c1fa7807e5d07a74c60203ffd1aade4a5a4
+    SHA512 a36825ab22be64c7c7b54861e88dea0bde5f0b80d32fc86b863e4409c820a25fea17cfbf2d068c1fdf4fb371714337dff390d31c983ea898fbdc37a09c469b4a
     HEAD_REF master
 )
 
diff --git a/ports/string-theory/vcpkg.json b/ports/string-theory/vcpkg.json
index 95880ba7ac..332d1ef969 100644
--- a/ports/string-theory/vcpkg.json
+++ b/ports/string-theory/vcpkg.json
@@ -1,6 +1,6 @@
 {
   "name": "string-theory",
-  "version": "3.8",
+  "version": "3.9",
   "description": "Flexible modern C++ string library with type-safe formatting.",
   "homepage": "https://github.com/zrax/string_theory",
   "license": "MIT",
diff --git a/versions/baseline.json b/versions/baseline.json
index 8fd57b018c..b3ebad2690 100644
--- a/versions/baseline.json
+++ b/versions/baseline.json
@@ -9269,7 +9269,7 @@
       "port-version": 2
     },
     "string-theory": {
-      "baseline": "3.8",
+      "baseline": "3.9",
       "port-version": 0
     },
     "string-view-lite": {
diff --git a/versions/s-/string-theory.json b/versions/s-/string-theory.json
index 77a43aa738..7b999f88e4 100644
--- a/versions/s-/string-theory.json
+++ b/versions/s-/string-theory.json
@@ -1,5 +1,10 @@
 {
   "versions": [
+    {
+      "git-tree": "5424eeefddbfceafd1f2dad16f468a1be7f1fc84",
+      "version": "3.9",
+      "port-version": 0
+    },
     {
       "git-tree": "ca2ab2f3286c4b1f945ea10f070bfb0845755018",
       "version": "3.8",