diff --git a/docs/FAQ.md b/docs/FAQ.md
index 1822e46b..4a9080f8 100644
--- a/docs/FAQ.md
+++ b/docs/FAQ.md
@@ -255,3 +255,18 @@ If you find an interesting or important question missing, submit it via
 
   Solution: `git pull ; make clean install` of AFL++.
 </p></details>
+
+<details>
+  <summary id="afl-map-size-warning">AFL++ map size warning.</summary><p>
+
+  When you run a large instrumented program stand-alone or via afl-showmap
+  you might see a warning like the following:
+
+  ```
+  Warning: AFL++ tools might need to set AFL_MAP_SIZE to 223723 to be able to run this instrumented program if this crashes!
+  ```
+
+  Depending how the target works it might also crash afterwards.
+
+  Solution: just do an `export AFL_MAP_SIZE=(the value in the warning)`.
+</p></details>
diff --git a/docs/INSTALL.md b/docs/INSTALL.md
index 4f2b7174..86ba916f 100644
--- a/docs/INSTALL.md
+++ b/docs/INSTALL.md
@@ -21,8 +21,8 @@ development state of AFL++.
 If you want to build AFL++ yourself, you have many options. The easiest choice
 is to build and install everything:
 
-NOTE: depending on your Debian/Ubuntu/Kali/... version release `-12` with
-whatever llvm version is available!
+NOTE: depending on your Debian/Ubuntu/Kali/... release, replace `-12` with
+whatever llvm version is available. We recommend llvm 12, 13 or 14.
 
 ```shell
 sudo apt-get update