diff --git a/svn_mirror/mirror.py b/svn_mirror/mirror.py
index c54691e..dbdf024 100644
--- a/svn_mirror/mirror.py
+++ b/svn_mirror/mirror.py
@@ -119,6 +119,7 @@ class Mirror:
             shutil.rmtree(import_dir)
 
         try:
+            self._cache_svn_credentials()
             self._run_git_svn_clone(import_dir)
             self._push_import_to_bare(import_dir)
             mappings = self._read_rev_maps(import_dir)
@@ -178,6 +179,27 @@ class Mirror:
         except subprocess.TimeoutExpired:
             raise MirrorError("git svn --version timed out")
 
+    def _cache_svn_credentials(self):
+        """Pre-populate SVN auth cache so git svn doesn't prompt."""
+        svn_cfg = self.config.svn
+        if not svn_cfg.username:
+            return
+        import subprocess
+        try:
+            r = subprocess.run(
+                ["svn", "info", "--non-interactive",
+                 svn_cfg.url.rstrip("/") + "/" + svn_cfg.trunk]
+                + svn_cfg.auth_args(),
+                capture_output=True, timeout=30,
+            )
+            if r.returncode != 0:
+                err = (r.stderr or b"").decode("utf-8", errors="replace").strip()
+                logger.warning("SVN credential cache failed (non-fatal): %s", err)
+            else:
+                logger.debug("SVN credentials cached")
+        except Exception as e:
+            logger.warning("SVN credential cache skipped: %s", e)
+
     def _run_git_svn_clone(self, target: Path):
         """Execute git svn clone --no-metadata for the initial import."""
         svn_cfg = self.config.svn
@@ -203,6 +225,7 @@ class Mirror:
 
         process = subprocess.Popen(
             args,
+            stdin=subprocess.DEVNULL,
             stdout=subprocess.PIPE,
             stderr=subprocess.STDOUT,
             text=True,