diff --git a/LOG b/LOG
index 6ee67a06d7..797320bc15 100644
--- a/LOG
+++ b/LOG
@@ -1419,10 +1419,20 @@
     BUILDING, c/vs.bat, wininstall/locate-vcredist.bat
 - fixed open-string-input-port on immutable strings
     cpnanopass.ss, io.ms, release_notes.stex
+- use setenv rather than putenv on non WIN32 environments
+    prim5.c, system.stex
 - restore {Free,Open,Net}BSD build, support Windows cross-compile
   via MinGW, add configuration options, and add helper makefile targets
     expenditor.c, thread.c, stats.c, statics.c, scheme.c, main.c, types.h,
     externs.h, globals.h, nocurses.h, version.h, system.h, segment.h,
     a6ob.def, ta6ob.def, a6nb.def, ta6nb.def, i3nt.def, ti3nt.def,
     c/Mf-*, build.bat, makefiles/Makefile.in, makefiles/Mf-install.in,
-    misc.ms, s/update-revision, BUILDING
+    s/update-revision, BUILDING
+- export `ee-backward-delete-sexp` binding in the expression-editor module.
+    expeditor.ss
+- fix ee_read_char to handle ^@ properly
+    expeditor.c
+- prevent access before start of array
+    scheme.c
+- remove dead stores in files
+    compress-io.c, new-io.c
diff --git a/c/compress-io.c b/c/compress-io.c
index 376cd03876..960dfb85b5 100644
--- a/c/compress-io.c
+++ b/c/compress-io.c
@@ -329,7 +329,7 @@ INT S_glzclose(glzFile glz) {
 #ifdef EINTR
           if (r < 0 && errno == EINTR) continue;
 #endif
-	  if (r == 0) { r = Z_ERRNO; saved_errno = errno; }
+	  if (r == 0) { saved_errno = errno; }
           break;
         }
         (void)LZ4F_freeDecompressionContext(lz4->dctx);
diff --git a/c/expeditor.c b/c/expeditor.c
index 5a6a50788c..c16865bc1e 100644
--- a/c/expeditor.c
+++ b/c/expeditor.c
@@ -691,11 +691,15 @@ static ptr s_ee_read_char(IBOOL blockp) {
 #endif /* PTHREADS */
 
     if (n == 1) {
-      old_locale = uselocale(term_locale);
-      sz = mbrtowc(&wch, buf, 1, &term_out_mbs);
-      uselocale(old_locale);
-      if (sz == 1) {
-        return Schar(wch);
+      if (buf[0] == '\0') {
+        return Schar('\0');
+      } else {
+        old_locale = uselocale(term_locale);
+        sz = mbrtowc(&wch, buf, 1, &term_out_mbs);
+        uselocale(old_locale);
+        if (sz == 1) {
+          return Schar(wch);
+        }
       }
     }
 
diff --git a/c/new-io.c b/c/new-io.c
index 2a896c19eb..74ed098b1f 100644
--- a/c/new-io.c
+++ b/c/new-io.c
@@ -842,8 +842,6 @@ ptr S_bytevector_compress(ptr dest_bv, iptr d_start, iptr d_count,
         if (!is_valid_lz4_length(s_count))
           return Sstring("source bytevector ~s is too large");
 
-        destLen = (int)d_count;
-
         destLen = LZ4_compress_default((char *)&BVIT(src_bv, s_start), (char *)&BVIT(dest_bv, d_start), (int)s_count, (int)d_count);
 
         if (destLen > 0)
diff --git a/c/prim5.c b/c/prim5.c
index c8ba26424e..414a12dfed 100644
--- a/c/prim5.c
+++ b/c/prim5.c
@@ -1372,11 +1372,7 @@ static void s_putenv(name, value) char *name, *value; {
   if (rc == 0)
     S_error1("putenv", "environment extension failed: ~a", S_LastErrorString());
 #else /* WIN32 */
-  iptr n; char *s;
-  n = strlen(name) + strlen(value) + 2;
-  if ((s = malloc(n)) == (char *)NULL
-       || snprintf(s, n, "%s=%s", name, value) < 0
-       || putenv(s) != 0) {
+  if (setenv(name, value, 1) != 0) {
     ptr msg = S_strerror(errno);
 
     if (msg != Sfalse)
diff --git a/c/scheme.c b/c/scheme.c
index 91eefaeeee..d94a989e3e 100644
--- a/c/scheme.c
+++ b/c/scheme.c
@@ -534,7 +534,7 @@ static IBOOL next_path(path, name, ext, sp, dsp) char *path; const char *name, *
   /* unless entry was null, append name and ext onto path and return true with
    * updated path, sp, and possibly dsp */
     if (s != *sp) {
-      if (!DIRMARKERP(*(p - 1))) { setp(PATHSEP); }
+      if ((p > path) && !DIRMARKERP(*(p - 1))) { setp(PATHSEP); }
       t = name;
       while (*t != 0) setp(*t++);
       t = ext;
diff --git a/csug/system.stex b/csug/system.stex
index 005a456ccc..807b99b52d 100644
--- a/csug/system.stex
+++ b/csug/system.stex
@@ -5329,8 +5329,6 @@ is associated with \var{key}.
 environment of the process,
 where it is available to the current process (e.g., via \var{getenv})
 and any spawned processes.
-The key and value are copied into storage allocated outside of
-the Scheme heap; this space is never reclaimed on non-Windows systems.
 
 \schemedisplay
 (putenv "SCHEME" "rocks!")
diff --git a/release_notes/release_notes.stex b/release_notes/release_notes.stex
index dd80ef4e71..bf0a485517 100644
--- a/release_notes/release_notes.stex
+++ b/release_notes/release_notes.stex
@@ -1749,6 +1749,12 @@ in fasl files does not generally make sense.
 %-----------------------------------------------------------------------------
 \section{Bug Fixes}\label{section:bugfixes}
 
+\subsection{\protect\code{putenv} memory leak (9.5.3)}
+
+\scheme{putenv} now calls the host system's \scheme{setenv} instead of
+\scheme{putenv} on non-Windows hosts and avoids allocating memory that
+is never freed, although \scheme{setenv} might do so.
+
 \subsection{String ports from immutable strings (9.5.4)}
 
 A bug that miscalculated the buffer size for
diff --git a/s/expeditor.ss b/s/expeditor.ss
index fadd08827d..04e554d4b6 100644
--- a/s/expeditor.ss
+++ b/s/expeditor.ss
@@ -82,8 +82,8 @@
              ee-beginning-of-entry ee-end-of-entry
              ee-delete-to-eol ee-delete-line
              ee-delete-between-point-and-mark ee-set-mark
-             ee-delete-entry ee-reset-entry ee-delete-sexp ee-redisplay
-             ee-yank-kill-buffer ee-yank-selection
+             ee-delete-entry ee-reset-entry ee-delete-sexp ee-backward-delete-sexp
+             ee-redisplay ee-yank-kill-buffer ee-yank-selection
              ee-string-macro ee-eof ee-delete-char ee-eof/delete-char
              ee-backward-delete-char ee-insert-paren
              ee-flash-matching-delimiter ee-goto-matching-delimiter