diff --git a/doc/stub/os.lua b/doc/stub/os.lua
index a2b5f5e08..ff7d88f58 100644
--- a/doc/stub/os.lua
+++ b/doc/stub/os.lua
@@ -95,10 +95,10 @@ function pullEventRaw(filter) end
 -- nearest multiple of 0.05.
 function sleep(time) end
 
---- Get the current CraftOS version (for example, `CraftOS 1.8`).
+--- Get the current CraftOS version (for example, `CraftOS 1.9`).
 --
 -- This is defined by `bios.lua`. For the current version of CC:Tweaked, this
--- should return `CraftOS 1.8`.
+-- should return `CraftOS 1.9`.
 --
 -- @treturn string The current CraftOS version.
 -- @usage os.version()
diff --git a/projects/core/src/main/resources/data/computercraft/lua/bios.lua b/projects/core/src/main/resources/data/computercraft/lua/bios.lua
index 64bb5283d..2ba511e82 100644
--- a/projects/core/src/main/resources/data/computercraft/lua/bios.lua
+++ b/projects/core/src/main/resources/data/computercraft/lua/bios.lua
@@ -31,7 +31,7 @@ _G.bit = {
 
 -- Install lua parts of the os api
 function os.version()
-    return "CraftOS 1.8"
+    return "CraftOS 1.9"
 end
 
 function os.pullEventRaw(sFilter)
diff --git a/projects/core/src/test/resources/test-rom/spec/programs/shell_spec.lua b/projects/core/src/test/resources/test-rom/spec/programs/shell_spec.lua
index 92e19172a..bdd4ed99c 100644
--- a/projects/core/src/test/resources/test-rom/spec/programs/shell_spec.lua
+++ b/projects/core/src/test/resources/test-rom/spec/programs/shell_spec.lua
@@ -214,7 +214,7 @@ describe("The shell", function()
             local lines = {}
             for i = 1, 5 do lines[i] = win.getLine(i):gsub(" +$", "") end
             expect(lines):same {
-                "CraftOS 1.8",
+                "CraftOS 1.9",
                 "> xyz",
                 "Transferring transfer.txt",
                 "> xyz",