diff --git a/.github/workflows/builds.yml b/.github/workflows/builds.yml
index 0007322ff4..b393e21ac5 100644
--- a/.github/workflows/builds.yml
+++ b/.github/workflows/builds.yml
@@ -1115,7 +1115,6 @@ jobs:
                 libjansson-dev \
                 libpython2.7 \
                 make \
-                mscgen \
                 parallel \
                 python3-yaml \
                 rustc \
diff --git a/.readthedocs.yaml b/.readthedocs.yaml
index f3fa6e66c5..bc23deb5f0 100644
--- a/.readthedocs.yaml
+++ b/.readthedocs.yaml
@@ -7,7 +7,3 @@ python:
   # Use an empty install section to avoid RTD from picking up a non-python
   # requirements.txt file.
   install: []
-
-build:
-  apt_packages:
-    - mscgen
diff --git a/Makefile.am b/Makefile.am
index cb101f708b..b061fa475e 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -6,7 +6,8 @@ EXTRA_DIST = ChangeLog COPYING LICENSE suricata.yaml.in \
              threshold.config \
              $(SURICATA_UPDATE_DIR) \
 	     lua \
-	     acsite.m4
+	     acsite.m4 \
+	     scripts/generate-images.sh
 SUBDIRS = $(HTP_DIR) rust src qa rules doc contrib etc python ebpf \
           $(SURICATA_UPDATE_DIR)
 
diff --git a/configure.ac b/configure.ac
index 754237da12..89ee81adb4 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2168,18 +2168,6 @@ fi
         AC_DEFINE([CLS],[64],[L1 cache line size])
     fi
 
-# mscgen for devguide images
-    AC_PATH_PROG([HAVE_MSCGEN], mscgen, "no")
-    if test "$HAVE_MSCGEN" = "no"; then
-        enable_mscgen=no
-        echo "WARNING! mscgen package not installed."
-        echo "    Devguide images won't be generated!"
-        echo "    Get mscgen package:"
-        echo "    https://www.mcternan.me.uk/mscgen/"
-        echo "    or install it from your distribution"
-    fi
-    AM_CONDITIONAL([HAVE_MSCGEN], [test "x$enable_mscgen" != "xno" ])
-
 # sphinx for documentation
     AC_PATH_PROG(HAVE_SPHINXBUILD, sphinx-build, "no")
     if test "$HAVE_SPHINXBUILD" = "no"; then
diff --git a/doc/userguide/Makefile.am b/doc/userguide/Makefile.am
index e535462a8a..8da69b757e 100644
--- a/doc/userguide/Makefile.am
+++ b/doc/userguide/Makefile.am
@@ -89,6 +89,5 @@ clean-local:
 	rm -rf $(top_builddir)/doc/userguide/_build
 	rm -f $(top_builddir)/doc/userguide/suricata*.1
 	rm -f $(top_builddir)/doc/userguide/userguide.pdf
-	rm -f $(top_builddir)/doc/userguide/devguide/extending/app-layer/diagrams/*.png
 
 endif # HAVE_SPHINXBUILD
diff --git a/doc/userguide/conf.py b/doc/userguide/conf.py
index 1cb1287d2a..36570c1654 100644
--- a/doc/userguide/conf.py
+++ b/doc/userguide/conf.py
@@ -135,6 +135,11 @@ if not on_rtd:
         html_theme_path = [sphinx_rtd_theme.get_html_theme_path()]
     except:
         html_theme = 'default'
+    def setup(app):
+        if hasattr(app, 'add_css_file'):
+            app.add_css_file('css/suricata.css')
+        else:
+            app.add_stylesheet('css/suricata.css')
 else:
     html_context = {
         'css_files': [
@@ -144,15 +149,6 @@ else:
         ],
     }
 
-def setup(app):
-    # Generate images.
-    subprocess.check_call("./devguide/tools/generate-images.sh")
-    if not on_rtd:
-        if hasattr(app, 'add_css_file'):
-            app.add_css_file('css/suricata.css')
-        else:
-            app.add_stylesheet('css/suricata.css')
-
 # Theme options are theme-specific and customize the look and feel of a theme
 # further.  For a list of options available for each theme, see the
 # documentation.
diff --git a/doc/userguide/devguide/.gitignore b/doc/userguide/devguide/.gitignore
deleted file mode 100644
index 507d52cdc5..0000000000
--- a/doc/userguide/devguide/.gitignore
+++ /dev/null
@@ -1 +0,0 @@
-extending/app-layer/diagrams/*.png
diff --git a/doc/userguide/devguide/extending/app-layer/diagrams/DnsUnidirectionalTransactions.png b/doc/userguide/devguide/extending/app-layer/diagrams/DnsUnidirectionalTransactions.png
new file mode 100644
index 0000000000..611ae3167f
Binary files /dev/null and b/doc/userguide/devguide/extending/app-layer/diagrams/DnsUnidirectionalTransactions.png differ
diff --git a/doc/userguide/devguide/extending/app-layer/diagrams/HTTP2BidirectionalTransaction.png b/doc/userguide/devguide/extending/app-layer/diagrams/HTTP2BidirectionalTransaction.png
new file mode 100644
index 0000000000..02de5dc6dd
Binary files /dev/null and b/doc/userguide/devguide/extending/app-layer/diagrams/HTTP2BidirectionalTransaction.png differ
diff --git a/doc/userguide/devguide/extending/app-layer/diagrams/TemplateTransaction.png b/doc/userguide/devguide/extending/app-layer/diagrams/TemplateTransaction.png
new file mode 100644
index 0000000000..89daed4fb8
Binary files /dev/null and b/doc/userguide/devguide/extending/app-layer/diagrams/TemplateTransaction.png differ
diff --git a/doc/userguide/devguide/extending/app-layer/diagrams/TlsHandshake.png b/doc/userguide/devguide/extending/app-layer/diagrams/TlsHandshake.png
new file mode 100644
index 0000000000..4be7b0441a
Binary files /dev/null and b/doc/userguide/devguide/extending/app-layer/diagrams/TlsHandshake.png differ
diff --git a/doc/userguide/devguide/tools/generate-images.sh b/scripts/generate-images.sh
similarity index 90%
rename from doc/userguide/devguide/tools/generate-images.sh
rename to scripts/generate-images.sh
index 5db3f953cf..b50b75e0c4 100755
--- a/doc/userguide/devguide/tools/generate-images.sh
+++ b/scripts/generate-images.sh
@@ -8,7 +8,7 @@ parent_path=$(cd "$(dirname "${BASH_SOURCE[0]}")" ; pwd -P)
 set -e
 
 cd "$parent_path"
-cd ../extending/app-layer/diagrams
+cd ../doc/userguide/devguide/extending/app-layer/diagrams
 
 for FILE in *.msc ; do
     # call mscgen and convert each file in images dir