diff --git a/cpython-unix/build-cpython.sh b/cpython-unix/build-cpython.sh
index 2c4e58501..c590e2fda 100755
--- a/cpython-unix/build-cpython.sh
+++ b/cpython-unix/build-cpython.sh
@@ -323,6 +323,12 @@ if [ -n "${PYTHON_MEETS_MINIMUM_VERSION_3_14}" ]; then
     patch -p1 -i ${ROOT}/patch-python-relative-build-details.patch
 fi
 
+# Mark the COLORS global variable static to prevent it from
+# conflicting with the symbol in the ncurses library.
+if [ -n "${PYTHON_MEETS_MINIMUM_VERSION_3_15}" ]; then
+    patch -p1 -i ${ROOT}/patch-optimizer-static-colors.patch
+fi
+
 # Most bits look at CFLAGS. But setup.py only looks at CPPFLAGS.
 # So we need to set both.
 CFLAGS="${EXTRA_TARGET_CFLAGS} -fPIC -I${TOOLS_PATH}/deps/include -I${TOOLS_PATH}/deps/include/ncursesw"
diff --git a/cpython-unix/patch-optimizer-static-colors.patch b/cpython-unix/patch-optimizer-static-colors.patch
new file mode 100644
index 000000000..6b8ef77f1
--- /dev/null
+++ b/cpython-unix/patch-optimizer-static-colors.patch
@@ -0,0 +1,13 @@
+diff --git a/Python/optimizer.c b/Python/optimizer.c
+index a2a1feb8b9e..c5f47d7f22c 100644
+--- a/Python/optimizer.c
++++ b/Python/optimizer.c
+@@ -2009,7 +2009,7 @@ find_line_number(PyCodeObject *code, _PyExecutorObject *executor)
+ #define BLACK "#000000"
+ #define LOOP "#00c000"
+ 
+-const char *COLORS[10] = {
++static const char *COLORS[10] = {
+     "9",
+     "8",
+     "7",
diff --git a/pythonbuild/downloads.py b/pythonbuild/downloads.py
index 8ae55371b..63588335e 100644
--- a/pythonbuild/downloads.py
+++ b/pythonbuild/downloads.py
@@ -93,10 +93,10 @@
         "python_tag": "cp314",
     },
     "cpython-3.15": {
-        "url": "https://www.python.org/ftp/python/3.15.0/Python-3.15.0a4.tar.xz",
-        "size": 34778104,
-        "sha256": "a0a521d5c480b89979da1aefce29750eb158128c0178728ebfef7511c21b4e77",
-        "version": "3.15.0a4",
+        "url": "https://www.python.org/ftp/python/3.15.0/Python-3.15.0a5.tar.xz",
+        "size": 34829268,
+        "sha256": "fee40da6450b67547c079dcb2852e8a03db6d57e06415466b2d3294449db22ef",
+        "version": "3.15.0a5",
         "licenses": ["Python-2.0", "CNRI-Python"],
         "license_file": "LICENSE.cpython.txt",
         "python_tag": "cp315",