diff --git a/src/H5.c b/src/H5.c
index 63d7aa15a26..839edf76b55 100644
--- a/src/H5.c
+++ b/src/H5.c
@@ -154,6 +154,9 @@ H5_init_library(void)
      */
     H5_INIT_GLOBAL = true;
 
+    /* Make sure we picked a good type for ssize_t if it wasn't present */
+    HDcompile_assert(sizeof(size_t) == sizeof(ssize_t));
+
 #ifdef H5_HAVE_PARALLEL
     {
         int mpi_initialized;
diff --git a/src/H5private.h b/src/H5private.h
index eacf0a70b58..769e6c93d1b 100644
--- a/src/H5private.h
+++ b/src/H5private.h
@@ -371,7 +371,7 @@
  * Only needed where ssize_t isn't a thing (e.g., Windows)
  */
 #ifndef SSIZE_MAX
-#define SSIZE_MAX ((ssize_t)(((size_t)1 << (8 * sizeof(ssize_t) - 1)) - 1))
+#define SSIZE_MAX SSIZE_T_MAX
 #endif
 
 /*
diff --git a/src/H5public.h b/src/H5public.h
index 09c46e15f8e..9bde45806c4 100644
--- a/src/H5public.h
+++ b/src/H5public.h
@@ -289,21 +289,11 @@ typedef int htri_t;
  *
  * Use of ssize_t should be discouraged in new code.
  */
-#if H5_SIZEOF_SSIZE_T == 0
-/* Undefine this size, we will re-define it in one of the sections below */
-#undef H5_SIZEOF_SSIZE_T
-#if H5_SIZEOF_SIZE_T == H5_SIZEOF_INT
-typedef int ssize_t;
-#define H5_SIZEOF_SSIZE_T H5_SIZEOF_INT
-#elif H5_SIZEOF_SIZE_T == H5_SIZEOF_LONG
-typedef long ssize_t;
-#define H5_SIZEOF_SSIZE_T H5_SIZEOF_LONG
-#elif H5_SIZEOF_SIZE_T == H5_SIZEOF_LONG_LONG
-typedef long long ssize_t;
-#define H5_SIZEOF_SSIZE_T H5_SIZEOF_LONG_LONG
-#else /* Can't find matching type for ssize_t */
-#error "nothing appropriate for ssize_t"
-#endif
+#if defined(_WIN32) && !defined(__MINGW32__)
+#include <BaseTsd.h>
+typedef SSIZE_T ssize_t;
+/* This will have been defined to 0 in configure */
+#define H5_SIZEOF_SSIZE_T H5_SIZEOF_SIZE_T
 #endif
 
 /**