diff --git a/misc.h b/misc.h
index c4f0e14c..be9ff9c0 100644
--- a/misc.h
+++ b/misc.h
@@ -26,6 +26,7 @@ char *host_strrchr(const char *s, int c);
 char *host_strduptrim(const char *s);
 
 char *dupstr(const char *s);
+wchar_t *dupwcs(const wchar_t *s);
 char *dupcat_fn(const char *s1, ...);
 #define dupcat(...) dupcat_fn(__VA_ARGS__, (const char *)NULL)
 char *dupprintf(const char *fmt, ...) PRINTF_LIKE(1, 2);
diff --git a/utils/CMakeLists.txt b/utils/CMakeLists.txt
index 3e43d4d7..38882059 100644
--- a/utils/CMakeLists.txt
+++ b/utils/CMakeLists.txt
@@ -25,6 +25,7 @@ add_sources_from_current_dir(utils
   dupcat.c
   dupprintf.c
   dupstr.c
+  dupwcs.c
   dup_mb_to_wc.c
   dup_wc_to_mb.c
   encode_utf8.c
diff --git a/utils/dupwcs.c b/utils/dupwcs.c
new file mode 100644
index 00000000..11fba330
--- /dev/null
+++ b/utils/dupwcs.c
@@ -0,0 +1,19 @@
+/*
+ * Allocate a duplicate of a NUL-terminated wchar_t string.
+ */
+
+#include <wchar.h>
+
+#include "defs.h"
+#include "misc.h"
+
+wchar_t *dupwcs(const wchar_t *s)
+{
+    wchar_t *p = NULL;
+    if (s) {
+        int len = wcslen(s);
+        p = snewn(len + 1, wchar_t);
+        wcscpy(p, s);
+    }
+    return p;
+}