diff --git a/Misc/NEWS.d/next/Build/2026-10-15-11-20-48.gh-issue-159440.uIz6ms.rst b/Misc/NEWS.d/next/Build/2026-10-15-11-20-48.gh-issue-159440.uIz6ms.rst
new file mode 100644
index 000000000000000..6c6cc43fd2e60d0
--- /dev/null
+++ b/Misc/NEWS.d/next/Build/2026-10-15-11-20-48.gh-issue-159440.uIz6ms.rst
@@ -0,0 +1,3 @@
+The version string reported by ``sys.version`` no longer carries a spurious
+``-dirty`` suffix when CPython is built out-of-tree from a clean git checkout:
+the build stamp now checks the source tree instead of the build directory.
diff --git a/configure b/configure
index a628d337003b1ef..217d8e135600e16 100755
--- a/configure
+++ b/configure
@@ -3694,9 +3694,9 @@ HAS_GIT=no-repository
 fi
 if test $HAS_GIT = found
 then
-    GITVERSION="git --git-dir \$(srcdir)/.git rev-parse --short HEAD"
-    GITTAG="git --git-dir \$(srcdir)/.git describe --all --always --dirty"
-    GITBRANCH="git --git-dir \$(srcdir)/.git name-rev --name-only HEAD"
+    GITVERSION="git --git-dir \$(srcdir)/.git --work-tree \$(srcdir) rev-parse --short HEAD"
+    GITTAG="git --git-dir \$(srcdir)/.git --work-tree \$(srcdir) describe --all --always --dirty"
+    GITBRANCH="git --git-dir \$(srcdir)/.git --work-tree \$(srcdir) name-rev --name-only HEAD"
 else
     GITVERSION=""
     GITTAG=""
diff --git a/configure.ac b/configure.ac
index cf01e6fa82bceb6..ca804d6448810d2 100644
--- a/configure.ac
+++ b/configure.ac
@@ -128,9 +128,9 @@ HAS_GIT=no-repository
 fi
 if test $HAS_GIT = found
 then
-    GITVERSION="git --git-dir \$(srcdir)/.git rev-parse --short HEAD"
-    GITTAG="git --git-dir \$(srcdir)/.git describe --all --always --dirty"
-    GITBRANCH="git --git-dir \$(srcdir)/.git name-rev --name-only HEAD"
+    GITVERSION="git --git-dir \$(srcdir)/.git --work-tree \$(srcdir) rev-parse --short HEAD"
+    GITTAG="git --git-dir \$(srcdir)/.git --work-tree \$(srcdir) describe --all --always --dirty"
+    GITBRANCH="git --git-dir \$(srcdir)/.git --work-tree \$(srcdir) name-rev --name-only HEAD"
 else
     GITVERSION=""
     GITTAG=""