diff --git a/man5/proc.5 b/man5/proc.5
index b24c6c8ef..dcf820a69 100644
--- a/man5/proc.5
+++ b/man5/proc.5
@@ -3637,10 +3637,14 @@ fail due to lack of memory once that memory has been successfully allocated.
 Total size of vmalloc memory area.
 .TP
 .IR VmallocUsed " %lu"
-Amount of vmalloc area which is used.
+Amount of vmalloc area which is used.  Since Linux 4.4, this field is no
+longer calculated, and is hard coded as 0.  See
+.IR /proc/vmallocinfo .
 .TP
 .IR VmallocChunk " %lu"
-Largest contiguous block of vmalloc area which is free.
+Largest contiguous block of vmalloc area which is free.  Since Linux 4.4,
+this field is no longer calculated is hard coded as 0.  See
+.IR /proc/vmallocinfo .
 .TP
 .IR HardwareCorrupted " %lu (since Linux 2.6.32)"
 (\fBCONFIG_MEMORY_FAILURE\fP is required.)