diff --git a/configure b/configure
index 1f8f756cec48e9fa3da8dc3046f0a5ccc08ac0f3..9eafe668db21a589af3f39cfb64c4ca1e26360fc 100755
--- a/configure
+++ b/configure
@@ -17095,7 +17095,7 @@ fi
 done
 
 
-for ac_func in asprintf atexit closefrom dup2 eaccess endpwent euidaccess ffsll ftruncate getcwd gethostbyname gethostname getloadavg gettimeofday glob ioperm inet_ntoa isascii memchr memmove memset mkdir mkdtemp munmap newlocale ppoll putenv re_comp regcomp select setenv socket strcasecmp strcasestr strchr strcspn strdup strerror strlcat strlcpy strncasecmp strndup strnlen strrchr strsep strspn strstr strtod strtol strtold strtoq unsetenv uselocale utime vasprintf getpeereid sysctl swapctl
+for ac_func in asprintf atexit closefrom dup2 eaccess endpwent euidaccess ffsll ftruncate getcwd gethostbyname gethostname getloadavg gettimeofday glob ioperm inet_ntoa isascii memchr memmove memset mkdir mkdtemp munmap newlocale ppoll putenv re_comp regcomp select setenv socket strcasecmp strcasestr strchr strcspn strdup strerror strlcat strlcpy strncasecmp strndup strnlen strrchr strsep strspn strstr strtod strtol strtold strtoq unsetenv uselocale utime vasprintf getpeereid sysctl swapctl malloc_trim
 do :
   as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
 ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"
diff --git a/configure.ac b/configure.ac
index d1ea560a1f74af932ef41afce21450d521c1c096..94a66336e54cc18ad9a413700a096887cef37184 100644
--- a/configure.ac
+++ b/configure.ac
@@ -794,7 +794,7 @@ AC_FUNC_STRNLEN
 AC_FUNC_STRTOD
 AC_FUNC_UTIME_NULL
 AC_FUNC_VPRINTF
-AC_CHECK_FUNCS([asprintf atexit closefrom dup2 eaccess endpwent euidaccess ffsll ftruncate getcwd gethostbyname gethostname getloadavg gettimeofday glob ioperm inet_ntoa isascii memchr memmove memset mkdir mkdtemp munmap newlocale ppoll putenv re_comp regcomp select setenv socket strcasecmp strcasestr strchr strcspn strdup strerror strlcat strlcpy strncasecmp strndup strnlen strrchr strsep strspn strstr strtod strtol strtold strtoq unsetenv uselocale utime vasprintf getpeereid sysctl swapctl])
+AC_CHECK_FUNCS([asprintf atexit closefrom dup2 eaccess endpwent euidaccess ffsll ftruncate getcwd gethostbyname gethostname getloadavg gettimeofday glob ioperm inet_ntoa isascii memchr memmove memset mkdir mkdtemp munmap newlocale ppoll putenv re_comp regcomp select setenv socket strcasecmp strcasestr strchr strcspn strdup strerror strlcat strlcpy strncasecmp strndup strnlen strrchr strsep strspn strstr strtod strtol strtold strtoq unsetenv uselocale utime vasprintf getpeereid sysctl swapctl malloc_trim])
 
 AC_MSG_CHECKING(for htonll)
 AC_LINK_IFELSE(
diff --git a/include/asterisk/autoconfig.h.in b/include/asterisk/autoconfig.h.in
index edfb9bee5e2b75cb765c8c9606cce2beaa4de06d..f401e57270e39b9c062c928034f07bd15b397980 100644
--- a/include/asterisk/autoconfig.h.in
+++ b/include/asterisk/autoconfig.h.in
@@ -468,6 +468,9 @@
 /* Define to 1 if you have the <malloc.h> header file. */
 #undef HAVE_MALLOC_H
 
+/* Define to 1 if you have the `malloc_trim' function. */
+#undef HAVE_MALLOC_TRIM
+
 /* Define to 1 if you have the `memchr' function. */
 #undef HAVE_MEMCHR
 
diff --git a/main/cli.c b/main/cli.c
index dc75acb1288872d53e32fb861e85c89fbde7fd33..f980fc6397633d4a4d810c5e679d2dd603822ca3 100644
--- a/main/cli.c
+++ b/main/cli.c
@@ -1791,6 +1791,34 @@ static char *handle_cli_wait_fullybooted(struct ast_cli_entry *e, int cmd, struc
 	return CLI_SUCCESS;
 }
 
+
+#ifdef HAVE_MALLOC_TRIM
+	/* BUGBUG malloc_trim() is a libc specific function.  Non-portable. */
+	static char *handle_cli_malloc_trim(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
+	{
+		extern int malloc_trim(size_t __pad) __THROW;
+
+		switch (cmd) {
+		case CLI_INIT:
+			e->command = "malloc trim";
+			e->usage =
+				"Usage: malloc trim\n"
+				"       Try to give excess memory back to the OS.\n";
+			return NULL;
+		case CLI_GENERATE:
+			return NULL;
+		}
+
+		if (malloc_trim(0)) {
+			ast_cli(a->fd, "Returned some memory to the OS.\n");
+		} else {
+			ast_cli(a->fd, "No memory returned to the OS.\n");
+		}
+
+		return CLI_SUCCESS;
+	}
+#endif
+
 static char *handle_help(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a);
 
 static struct ast_cli_entry cli_cli[] = {
@@ -1837,6 +1865,11 @@ static struct ast_cli_entry cli_cli[] = {
 	AST_CLI_DEFINE(handle_cli_check_permissions, "Try a permissions config for a user"),
 
 	AST_CLI_DEFINE(handle_cli_wait_fullybooted, "Wait for Asterisk to be fully booted"),
+
+#ifdef HAVE_MALLOC_TRIM
+	AST_CLI_DEFINE(handle_cli_malloc_trim, "Return excess memory to the OS"),
+#endif
+
 };
 
 /*!