diff --git a/build-python312.patch b/build-python312.patch
new file mode 100644
index 0000000..add5bb4
--- /dev/null
+++ b/build-python312.patch
@@ -0,0 +1,12 @@
+diff -up thunderbird-115.0.1/mach.python312 thunderbird-115.0.1/mach
+--- thunderbird-115.0.1/mach.python312	2023-07-26 14:30:25.336532252 +0200
++++ thunderbird-115.0.1/mach	2023-07-26 14:31:19.056512905 +0200
+@@ -67,7 +67,7 @@ def try_alternate_python3_executables(ar
+ def main(args):
+     # Ensure we are running Python 3.7+. We run this check as soon as
+     # possible to avoid a cryptic import/usage error.
+-    if sys.version_info < MIN_PYTHON_VERSION:
++    if sys.version_info < MIN_PYTHON_VERSION or sys.version_info > MAX_PYTHON_VERSION_TO_CONSIDER:
+         print(f"Python {MIN_PYTHON_VERSION[0]}.{MIN_PYTHON_VERSION[1]}+ is required to run mach.")
+         print("You are running Mach with Python {0}".format(platform.python_version()))
+         try_alternate_python3_executables(args)
diff --git a/thunderbird.spec b/thunderbird.spec
index a5cef3f..b41977e 100644
--- a/thunderbird.spec
+++ b/thunderbird.spec
@@ -109,6 +109,7 @@ Patch103:       rhbz-1219542-s390-build.patch
 Patch422:       0001-GLIBCXX-fix-for-GCC-12.patch
 Patch425:       build-disable-elfhack.patch
 Patch426:       build-rnp.patch
+Patch427:       build-python312.patch
 
 # PPC fix
 Patch304:       mozilla-1245783.patch
@@ -278,6 +279,8 @@ debug %{name}, you want to install %{name}-debuginfo instead.
 %patch -P 425 -p1 -b .build-disable-elfhack
 %endif
 %patch -P 426 -p1 -b .build-rnp
+# python3.12 is not supported yet
+%patch -P 427 -p1 -b .build-python312
 # most likely fixed
 #%patch -P 419 -p1 -b .bindgen
 
@@ -518,10 +521,6 @@ MOZ_SMP_FLAGS=-j1
 
 export MOZ_MAKE_FLAGS="$MOZ_SMP_FLAGS"
 export STRIP=/bin/true
-export PYTHON=python3.11
-%if 0%{?fedora} >= 39
-alias python=python3.11
-%endif
 export MACH_BUILD_PYTHON_NATIVE_PACKAGE_SOURCE=system
 ./mach build -v