diff --git a/diagrams/attack-surface-vs-linux-compatibility.tex b/diagrams/attack-surface-vs-linux-compatibility.tex
index dfd204a..4e21789 100644
--- a/diagrams/attack-surface-vs-linux-compatibility.tex
+++ b/diagrams/attack-surface-vs-linux-compatibility.tex
@@ -1,6 +1,7 @@
 \documentclass[12pt,crop,tikz]{standalone}
 
 \providecommand{\rootdir}{..}
+\usepackage{tikz}
 \usetikzlibrary{backgrounds}
 \usetikzlibrary{positioning}
 \usetikzlibrary{calc}
diff --git a/diagrams/openbsd-syslogd-privsep.tex b/diagrams/openbsd-syslogd-privsep.tex
index 49613d1..a1658f1 100644
--- a/diagrams/openbsd-syslogd-privsep.tex
+++ b/diagrams/openbsd-syslogd-privsep.tex
@@ -1,6 +1,7 @@
 \documentclass[12pt,crop,tikz]{standalone}
 
 \providecommand{\rootdir}{..}
+\usepackage{tikz}
 \usetikzlibrary{backgrounds}
 \usetikzlibrary{positioning}
 \usetikzlibrary{calc}
diff --git a/diagrams/tls-server-processes.tex b/diagrams/tls-server-processes.tex
index ce77a8b..5e95bca 100644
--- a/diagrams/tls-server-processes.tex
+++ b/diagrams/tls-server-processes.tex
@@ -1,6 +1,7 @@
 \documentclass[12pt,crop,tikz]{standalone}
 
 \providecommand{\rootdir}{..}
+\usepackage{tikz}
 \usetikzlibrary{backgrounds}
 \usetikzlibrary{positioning}
 \usetikzlibrary{calc}