diff --git a/proc/meminfo.c b/proc/meminfo.c
index 3f949450..719ad3e7 100644
--- a/proc/meminfo.c
+++ b/proc/meminfo.c
@@ -699,7 +699,7 @@ static int meminfo_read_failed (
        such values will be dramatically distorted over those of the host. */
     if (mHr(MemAvailable) > mHr(MemTotal))
         mHr(MemAvailable) = mHr(MemFree);
-    mem_used = mHr(MemTotal) - mHr(MemFree) - mHr(derived_mem_cached) - mHr(Buffers);
+    mem_used = mHr(MemTotal) - mHr(MemAvailable);
     if (mem_used < 0)
         mem_used = mHr(MemTotal) - mHr(MemFree);
     mHr(derived_mem_used) = (unsigned long)mem_used;
diff --git a/proc/meminfo.h b/proc/meminfo.h
index 0f3d0076..1913abd1 100644
--- a/proc/meminfo.h
+++ b/proc/meminfo.h
@@ -89,7 +89,7 @@ enum meminfo_item {
     MEMINFO_MEM_SLAB_UNRECLAIM,    //   ul_int         "
     MEMINFO_MEM_TOTAL,             //   ul_int         "
     MEMINFO_MEM_UNEVICTABLE,       //   ul_int         "
-    MEMINFO_MEM_USED,              //   ul_int        derived from MEM_TOTAL - MEM_BUFFERS - MEM_CACHED_ALL - MEM_FREE
+    MEMINFO_MEM_USED,              //   ul_int        derived from MEM_TOTAL - MEM_AVAILABLE
     MEMINFO_MEM_VM_ALLOC_CHUNK,    //   ul_int        /proc/meminfo
     MEMINFO_MEM_VM_ALLOC_TOTAL,    //   ul_int         "
     MEMINFO_MEM_VM_ALLOC_USED,     //   ul_int         "