diff --git a/base/applications/taskmgr/perfdata.c b/base/applications/taskmgr/perfdata.c
index a19c0cb0d97..75c6c27fcd2 100644
--- a/base/applications/taskmgr/perfdata.c
+++ b/base/applications/taskmgr/perfdata.c
@@ -5,6 +5,7 @@
  *
  *  Copyright (C) 1999 - 2001  Brian Palmer                <brianp@reactos.org>
  *  Copyright (C)        2014  Ismael Ferreras Morezuelas  <swyterzone+ros@gmail.com>
+ *  Copyright (C)        2020  Aidan Case                  <aidanzcase@gmail.com>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -22,6 +23,8 @@
  */
 
 #include "precomp.h"
+#include "perfdata.h"
+#include "winbase.h"
 
 #define WIN32_LEAN_AND_MEAN
 #include <aclapi.h>
@@ -564,19 +567,50 @@ BOOL PerfDataGetCommandLine(ULONG Index, LPWSTR lpCommandLine, ULONG nMaxCount)
     LPWSTR new_string;
 
     PCMD_LINE_CACHE cache = global_cache;
+    PCMD_LINE_CACHE old_cache = NULL;
 
-    /* [A] Search for a string already in cache? If so, use it */
+    /* [A] Search for a string already in cache? If so, use it. If not, check if invalid and free it if so. */
     while (cache && cache->pnext != NULL)
     {
-        if (cache->idx == Index && cache->str != NULL)
+        if (cache->idx == Index && cache->pid == PerfDataGetProcessId(cache->idx) && cache->str != NULL)
         {
             /* Found it. Use it, and add some ellipsis at the very end to make it cute */
             wcsncpy(lpCommandLine, cache->str, CMD_LINE_MIN(nMaxCount, cache->len));
             wcscpy(lpCommandLine + CMD_LINE_MIN(nMaxCount, cache->len) - wcslen(ellipsis), ellipsis);
             return TRUE;
         }
-
-        cache = cache->pnext;
+        else if (cache->pid != PerfDataGetProcessId(cache->idx)) 
+        {
+            /* There has been a shift, and this node is no longer valid. Free it and recache it later. */
+            if (old_cache == NULL) 
+            {
+                /* Unless, of course, its the global_cache. In that case, just shift global_cache to the next node and then free it. */
+                old_cache = global_cache;
+                if (global_cache->pnext == NULL) 
+                {
+                    /* And we are out of cache. Whoops. */
+                    HeapFree(GetProcessHeap(), 0, old_cache);
+                    global_cache = NULL;
+                    break;
+                }
+                global_cache = global_cache->pnext;
+                cache = global_cache;
+                HeapFree(GetProcessHeap(), 0, old_cache);
+            } 
+            else 
+            {
+                /* We're in the middle of the cache, so we can safely shift nodes around. */
+                old_cache->pnext = cache->pnext;
+                HeapFree(GetProcessHeap(), 0, cache);
+                cache = old_cache->pnext;
+            }
+        } 
+        else 
+        {
+            /* This is not the cache you're looking for. */
+            old_cache = cache;
+            cache = cache->pnext;
+        }
     }
 
     /* [B] We don't; let's allocate and load a value from the process mem... and cache it */
@@ -642,6 +676,7 @@ BOOL PerfDataGetCommandLine(ULONG Index, LPWSTR lpCommandLine, ULONG nMaxCount)
     new_entry->idx = Index;
     new_entry->str = new_string;
     new_entry->len = CommandLineStr.Length;
+    new_entry->pid = ProcessId;
 
     if (!global_cache)
         global_cache = new_entry;
diff --git a/base/applications/taskmgr/perfdata.h b/base/applications/taskmgr/perfdata.h
index 51e11f47b2e..8bd3d33ad57 100644
--- a/base/applications/taskmgr/perfdata.h
+++ b/base/applications/taskmgr/perfdata.h
@@ -4,6 +4,7 @@
  *  perfdata.h
  *
  *  Copyright (C) 1999 - 2001  Brian Palmer  <brianp@reactos.org>
+ *  Copyright (C)        2020  Aidan Case    <aidanzcase@gmail.com>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -22,6 +23,7 @@
 
 #pragma once
 
+#include "windef.h"
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -58,6 +60,7 @@ typedef struct _PERFDATA
 typedef struct _CMD_LINE_CACHE
 {
      DWORD idx;
+     ULONG pid;
     LPWSTR str;
      ULONG len;
     struct _CMD_LINE_CACHE* pnext;