diff --git a/backend/src/langs.ts b/backend/src/langs.ts
index 858054b..814ca72 100644
--- a/backend/src/langs.ts
+++ b/backend/src/langs.ts
@@ -2002,6 +2002,21 @@ PLEASE GIVE UP
     template: `body:before {
   content: "Hello, world!";
 }
+`,
+  },
+  lisaac: {
+    name: "Lisaac",
+    main: "main.li",
+    compile: "lisaac -gcc -Wno-implicit-function-declaration main.li",
+    run: "./main",
+    template: `Section Header
+  + name := MAIN;
+
+Section Public
+  - main <-
+  (
+    "Hello, world!\\n".print;
+  );
 `,
   },
   livescript: {
diff --git a/scripts/docker-install-phase3b.bash b/scripts/docker-install-phase3b.bash
index 07e4f9e..1cd0b59 100755
--- a/scripts/docker-install-phase3b.bash
+++ b/scripts/docker-install-phase3b.bash
@@ -98,6 +98,9 @@ julia
 # Ksh
 ksh
 
+# Lisaac
+lisaac
+
 # LLVM
 llvm