diff --git a/cmake/cmake.h.in b/cmake/cmake.h.in
index 3d36b3d0..cb389cb6 100644
--- a/cmake/cmake.h.in
+++ b/cmake/cmake.h.in
@@ -15,6 +15,7 @@
 #cmakedefine01 HAVE_GETNAMEDPIPECLIENTPROCESSID
 #cmakedefine01 HAVE_SETDEFAULTDLLDIRECTORIES
 #cmakedefine01 HAVE_STRTOUMAX
+#cmakedefine01 HAVE_WMEMCHR
 #cmakedefine01 HAVE_DWMAPI_H
 
 #cmakedefine NOT_X_WINDOWS
diff --git a/cmake/platforms/windows.cmake b/cmake/platforms/windows.cmake
index 481809ec..e87f3380 100644
--- a/cmake/platforms/windows.cmake
+++ b/cmake/platforms/windows.cmake
@@ -53,6 +53,7 @@ define_negation(NO_HTMLHELP HAVE_HTMLHELP_H)
 check_include_files("winsock2.h;afunix.h" HAVE_AFUNIX_H)
 
 check_symbol_exists(strtoumax "inttypes.h" HAVE_STRTOUMAX)
+check_symbol_exists(wmemchr "wchar.h" HAVE_WMEMCHR)
 check_symbol_exists(AddDllDirectory "windows.h" HAVE_ADDDLLDIRECTORY)
 check_symbol_exists(SetDefaultDllDirectories "windows.h"
   HAVE_SETDEFAULTDLLDIRECTORIES)
diff --git a/defs.h b/defs.h
index 0ac23ee2..0e56eb78 100644
--- a/defs.h
+++ b/defs.h
@@ -53,6 +53,11 @@ uintmax_t strtoumax(const char *nptr, char **endptr, int base);
 #define SIZEu "zu"
 #endif
 
+#if !HAVE_WMEMCHR
+/* Work around lack of wmemchr in older MSVC */
+wchar_t *wmemchr(const wchar_t *s, wchar_t c, size_t n);
+#endif
+
 #if defined __GNUC__ || defined __clang__
 /*
  * On MinGW, the correct compiler format checking for vsnprintf() etc
diff --git a/windows/CMakeLists.txt b/windows/CMakeLists.txt
index 960a440d..7d4fcadb 100644
--- a/windows/CMakeLists.txt
+++ b/windows/CMakeLists.txt
@@ -42,6 +42,9 @@ add_sources_from_current_dir(utils
 if(NOT HAVE_STRTOUMAX)
   add_sources_from_current_dir(utils utils/strtoumax.c)
 endif()
+if(NOT HAVE_WMEMCHR)
+  add_sources_from_current_dir(utils utils/wmemchr.c)
+endif()
 add_sources_from_current_dir(eventloop
   cliloop.c handle-wait.c)
 add_sources_from_current_dir(console
diff --git a/windows/utils/getdlgitemtext_alloc.c b/windows/utils/getdlgitemtext_alloc.c
index 8db32901..8de62a3b 100644
--- a/windows/utils/getdlgitemtext_alloc.c
+++ b/windows/utils/getdlgitemtext_alloc.c
@@ -4,6 +4,8 @@
  * string is dynamically allocated; caller must free.
  */
 
+#include <wchar.h>
+
 #include "putty.h"
 
 char *GetDlgItemText_alloc(HWND hwnd, int id)
@@ -27,7 +29,7 @@ wchar_t *GetDlgItemTextW_alloc(HWND hwnd, int id)
     do {
         sgrowarray_nm(ret, size, size);
         GetDlgItemTextW(hwnd, id, ret, size);
-    } while (!memchr(ret, '\0', size-1));
+    } while (!wmemchr(ret, L'\0', size-1));
 
     return ret;
 }
diff --git a/windows/utils/wmemchr.c b/windows/utils/wmemchr.c
new file mode 100644
index 00000000..7ccdfe3c
--- /dev/null
+++ b/windows/utils/wmemchr.c
@@ -0,0 +1,15 @@
+/*
+ * Work around lack of wmemchr in older MSVC libraries.
+ */
+
+#include <wchar.h>
+
+#include "defs.h"
+
+wchar_t *wmemchr(const wchar_t *s, wchar_t c, size_t n)
+{
+    for (; n != 0; s++, n--)
+        if (*s == c)
+            return (wchar_t *)s;
+    return NULL;
+}