diff --git a/config/shared/zsh/completion.zsh b/config/shared/zsh/completion.zsh
index bc4c33e..cfb8d52 100644
--- a/config/shared/zsh/completion.zsh
+++ b/config/shared/zsh/completion.zsh
@@ -39,6 +39,19 @@ _selfishell_completion_files_changed() {
   return 1
 }
 
+# zcompile unlinks and recreates the read-only .zwc in place, so concurrent
+# shells fail with "can't write zwc file"; compile privately, then rename.
+# mv would move the file into a directory occupying the target, so skip one.
+_selfishell_completion_compile() {
+  local temporary="$ZCOMPDUMP.tmp.$$.$RANDOM.zwc"
+
+  [[ ! -d "$ZCOMPDUMP.zwc" ]] || return 1
+  zcompile "$temporary" "$ZCOMPDUMP" && command mv -f "$temporary" "$ZCOMPDUMP.zwc" || {
+    command rm -f "$temporary"
+    return 1
+  }
+}
+
 if [[ -o interactive ]] && { _selfishell_completion_needs_audit "$ZCOMPDUMP" ||
      _selfishell_completion_files_changed "$ZCOMPDUMP"; }; then
   # -i excludes insecure entries; -D rebuilds even when an unaudited dump has
@@ -56,7 +69,7 @@ if [[ -o interactive ]] && { _selfishell_completion_needs_audit "$ZCOMPDUMP" ||
     fi
     # Invalidate the old marker before rebuilding; a failed write must not
     # let the next shell skip the audit and restore insecure fpath entries.
-    if compdump && zcompile "$ZCOMPDUMP" && [[ "${_comp_secure:-}" != yes &&
+    if compdump && _selfishell_completion_compile && [[ "${_comp_secure:-}" != yes &&
          ! -e "$ZCOMPDUMP.audit" && ! -L "$ZCOMPDUMP.audit" ]]; then
       command touch "$ZCOMPDUMP.audit" 2>/dev/null
     fi
@@ -64,11 +77,12 @@ if [[ -o interactive ]] && { _selfishell_completion_needs_audit "$ZCOMPDUMP" ||
 else
   compinit -C -d "$ZCOMPDUMP"
 fi
-unfunction _selfishell_completion_needs_audit _selfishell_completion_files_changed
 
 if [[ -s "$ZCOMPDUMP" && ( ! -s "$ZCOMPDUMP.zwc" || "$ZCOMPDUMP" -nt "$ZCOMPDUMP.zwc" ) ]]; then
-  zcompile "$ZCOMPDUMP"
+  _selfishell_completion_compile
 fi
+unfunction _selfishell_completion_needs_audit _selfishell_completion_files_changed \
+  _selfishell_completion_compile
 
 if (( $+functions[zinit] )); then
   zinit cdreplay -q
diff --git a/tests/integration/native_completion_test.go b/tests/integration/native_completion_test.go
index 06cc471..b76dd02 100644
--- a/tests/integration/native_completion_test.go
+++ b/tests/integration/native_completion_test.go
@@ -275,6 +275,25 @@ func TestNativeCompletionAudit(t *testing.T) {
 	}
 }
 
+// Terminals restoring several tabs start shells that recompile the dump at once.
+// A directory occupying the bytecode path must not receive the compiled file.
+func TestNativeConcurrentDumpCompile(t *testing.T) {
+	t.Parallel()
+	home := nativeHome(t)
+	r := nativeRun(t, home, `startup='_selfishell_command_path() { return 1; }; source "$SELFISHELL_SOURCE"'
+zsh -fc "$startup"
+for i in {1..8}; do
+  zsh -fc "repeat 20; do command touch \"\$HOME/.zcompdump\"; $startup; done" &
+done
+wait
+command rm -f "$HOME/.zcompdump.zwc" && command mkdir "$HOME/.zcompdump.zwc" &&
+  command touch -t 202001010000 "$HOME/.zcompdump.zwc" || exit 10
+zsh -fc "$startup"
+leftovers=("$HOME"/.zcompdump.tmp*(DN) "$HOME"/.zcompdump.zwc/*(DN))
+(( ! $#leftovers )) || print -rl -- $leftovers`, "ZDOTDIR="+home, "SELFISHELL_SOURCE="+nativeCompletion())
+	nativeQuiet(t, r)
+}
+
 func nativeCompletionProbe(t *testing.T, home, dir, mode, compile string) capture {
 	t.Helper()
 	if mode == "" {