diff --git a/NEWS b/NEWS
index 12dbbc7d3ae..f8e6f5ee82f 100644
--- a/NEWS
+++ b/NEWS
@@ -30,6 +30,9 @@ PHP                                                                        NEWS
   . Fixed bugs GH-15908 and GH-15026 (leak / assertion failure in streams.c).
     (nielsdos)
 
+- TSRM:
+  . Prevent closing of unrelated handles. (cmb)
+
 - XML:
   . Fixed bug GH-15868 (Assertion failure in xml_parse_into_struct after
     exception). (nielsdos)
diff --git a/TSRM/tsrm_win32.c b/TSRM/tsrm_win32.c
index 0af03b6ed89..5d48ea2678a 100644
--- a/TSRM/tsrm_win32.c
+++ b/TSRM/tsrm_win32.c
@@ -707,6 +707,7 @@ TSRM_API int shmget(key_t key, size_t size, int flags)
 	if (NULL != shm->descriptor && (shm->descriptor->shm_perm.key != key || size > shm->descriptor->shm_segsz)) {
 		if (NULL != shm->segment) {
 			CloseHandle(shm->segment);
+			shm->segment = INVALID_HANDLE_VALUE;
 		}
 		UnmapViewOfFile(shm->descriptor);
 		shm->descriptor = NULL;