diff --git a/package/AUTHORS b/package/AUTHORS
index ed19d3ac17..83dd5c620e 100644
--- a/package/AUTHORS
+++ b/package/AUTHORS
@@ -287,7 +287,7 @@ Chronological list of authors
   - Francesco Siciliani
   - Akshit Boora
   - Sumit Saraswat
-
+  - Erik Fransson
 
 External code
 -------------
diff --git a/package/CHANGELOG b/package/CHANGELOG
index ed3d37a7fd..1ee57ec083 100644
--- a/package/CHANGELOG
+++ b/package/CHANGELOG
@@ -14,11 +14,17 @@ The rules for this file:
 
 
 -------------------------------------------------------------------------------
-??/??/?? IAlibay, sumitsaraswat362
+??/??/?? IAlibay, sumitsaraswat362, erikfransson
 
  * 2.12.0
 
 Fixes
+ * The NCDF reader now releases the pages of the memory map once a frame has
+   been read into the Timestep. Reading a netCDF trajectory with `mmap=True`
+   (the default for a file name) no longer grows the resident memory of the
+   process towards the size of the whole trajectory file. Requires a platform
+   that provides `MADV_DONTNEED`, i.e. not Windows (Discussion #4792,
+   PR #5463).
 
 Enhancements
  * InterRDF and InterRDF_s now expose computed average box volume and densities
diff --git a/package/MDAnalysis/coordinates/TRJ.py b/package/MDAnalysis/coordinates/TRJ.py
index e9799e4d94..6687093651 100644
--- a/package/MDAnalysis/coordinates/TRJ.py
+++ b/package/MDAnalysis/coordinates/TRJ.py
@@ -134,6 +134,7 @@
 import warnings
 import errno
 import logging
+import mmap
 from math import isclose
 
 import MDAnalysis
@@ -675,6 +676,10 @@ def _read_frame(self, frame):
                 self.convert_pos_from_native(ts.dimensions[:3])
         ts.frame = frame  # frame labels are 0-based
         self._current_frame = frame
+        # the frame is now copied into ts, so its pages can be dropped again
+        mm = getattr(self.trjfile, "_mm", None)
+        if mm is not None and hasattr(mmap, "MADV_DONTNEED"):
+            mm.madvise(mmap.MADV_DONTNEED)
         return ts
 
     def _reopen(self):