diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 46c1b56eb..34814f171 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -10,6 +10,17 @@ on:
     - master
 
 jobs:
+  validate:
+
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v1
+      - uses: ok-nick/setup-aftman@v0.4.2
+
+      - name: Validate Crate Versions
+        run: lune run validate-crate-versions
+
   build:
 
     runs-on: ubuntu-latest
diff --git a/.lune/semver.luau b/.lune/semver.luau
new file mode 100644
index 000000000..73ceda378
--- /dev/null
+++ b/.lune/semver.luau
@@ -0,0 +1,81 @@
+--!strict
+local SemVer = {}
+SemVer.__index = SemVer
+
+export type SemVer = {
+	major: number,
+	minor: number?,
+	patch: number?,
+}
+
+local function compare(a: number, b: number): number
+	if a > b then
+		return 1
+	elseif a < b then
+		return -1
+	end
+
+	return 0
+end
+
+function SemVer.__tostring(self: SemVer): string
+	return string.format("%i.%i.%i", self.major, self.minor or 0, self.patch or 0)
+end
+
+--[[
+	Constructs a new SemVer from the provided parts.
+]]
+function SemVer.new(major: number, minor: number?, patch: number?): SemVer
+	return (setmetatable({
+		major = major,
+		minor = minor,
+		patch = patch,
+	}, SemVer) :: any) :: SemVer
+end
+
+--[[
+    Parses `version` into a SemVer.
+]]
+function SemVer.parse(version: string)
+	local major, minor, patch, _ = version:match("^(%d+)%.(%d+)%.(%d+)(.*)$")
+	local realVersion = {
+		major = tonumber(major),
+		minor = tonumber(minor),
+		patch = tonumber(patch),
+	}
+	if realVersion.major == nil then
+		error(`could not parse major version from '{version}'`, 2)
+	end
+	if minor and realVersion.minor == nil then
+		error(`could not parse minor version from '{version}'`, 2)
+	end
+	if patch and realVersion.patch == nil then
+		error(`could not parse patch version from '{version}'`, 2)
+	end
+
+	return (setmetatable(realVersion, SemVer) :: any) :: SemVer
+end
+
+--[[
+	Compares two SemVers and returns their status compared to one another.
+	
+	If `1` is returned, a is 'newer' than b.
+	If `-1` is returned, a is 'older' than b.
+	If `0` is returned, they are identical.
+]]
+function SemVer.compare(a: SemVer, b: SemVer)
+	local major = compare(a.major, b.major)
+	local minor = compare(a.minor or 0, b.minor or 0)
+
+	if major ~= 0 then
+		return major
+	end
+
+	if minor ~= 0 then
+		return minor
+	end
+
+	return compare(a.patch or 0, b.patch or 0)
+end
+
+return SemVer
diff --git a/.lune/validate-crate-versions.luau b/.lune/validate-crate-versions.luau
new file mode 100644
index 000000000..45d9b7ca1
--- /dev/null
+++ b/.lune/validate-crate-versions.luau
@@ -0,0 +1,107 @@
+--!strict
+--#selene: allow(incorrect_standard_library_use)
+
+local IGNORE_CRATE_LIST = {
+	"rbx_util",
+	"rbx_reflector",
+}
+
+local fs = require("@lune/fs")
+local serde = require("@lune/serde")
+local stdio = require("@lune/stdio")
+local process = require("@lune/process")
+
+local SemVer = require("semver")
+
+type WorkspaceCargo = {
+	workspace: {
+		members: { string },
+	},
+}
+
+type CrateCargo = {
+	package: {
+		name: string,
+		version: string,
+	},
+	dependencies: { [string]: Dependency },
+	["dev-dependencies"]: { [string]: Dependency }?,
+}
+
+type Dependency = string | { version: string?, path: string?, features: { string }, optional: boolean? }
+
+local function warn(...)
+	stdio.write(`[{stdio.color("yellow")}WARN{stdio.color("reset")}] `)
+	print(...)
+end
+
+local function processDependencies(dependency_list: { [string]: Dependency }, output: { [string]: Dependency })
+	for name, dependency in dependency_list do
+		if typeof(dependency) == "string" then
+			continue
+		end
+		if dependency.path then
+			output[name] = dependency
+		end
+	end
+end
+
+local workspace: WorkspaceCargo = serde.decode("toml", fs.readFile("Cargo.toml"))
+
+local crate_info = {}
+
+for _, crate_name in workspace.workspace.members do
+	if table.find(IGNORE_CRATE_LIST, crate_name) then
+		continue
+	end
+	local cargo: CrateCargo = serde.decode("toml", fs.readFile(`{crate_name}/Cargo.toml`))
+	local dependencies = {}
+	local dev_dependencies = {}
+	processDependencies(cargo.dependencies, dependencies)
+	if cargo.package["dev-dependencies"] then
+		processDependencies(cargo["dev-dependencies"] :: any, dev_dependencies)
+	end
+	crate_info[crate_name] = {
+		version = SemVer.parse(cargo.package.version),
+		dependencies = dependencies,
+		dev_dependencies = dev_dependencies,
+	}
+end
+
+table.freeze(crate_info)
+
+local all_ok = true
+
+for crate_name, cargo in crate_info do
+	for name, dependency in cargo.dependencies do
+		if typeof(dependency) == "string" then
+			error("invariant: string dependency made it into path list")
+		end
+		if not crate_info[name] then
+			warn(`Dependency {name} of crate {crate_name} has a path but is not local to this workspace.`)
+			all_ok = false
+			continue
+		end
+		if not dependency.version then
+			warn(`Dependency {name} of crate {crate_name} has a path but no version specified. Please fix this.`)
+			all_ok = false
+			continue
+		end
+		local dependency_version = SemVer.parse(dependency.version :: string)
+		local cmp = SemVer.compare(crate_info[name].version, dependency_version)
+		if cmp == 0 then
+			continue
+		else
+			all_ok = false
+			warn(
+				`Dependency {name} of crate {crate_name} has a version mismatch. Current version: {dependency_version}. Should be: {crate_info[name].version}`
+			)
+		end
+	end
+end
+
+if all_ok then
+	process.exit(0)
+else
+	process.exit(1)
+end
diff --git a/aftman.toml b/aftman.toml
index b1bd6be64..0364079bf 100644
--- a/aftman.toml
+++ b/aftman.toml
@@ -3,3 +3,4 @@ rojo = "rojo-rbx/rojo@7.3.0"
 run-in-roblox = "rojo-rbx/run-in-roblox@0.3.0"
 selene = "Kampfkarren/selene@0.25.0"
 stylua = "JohnnyMorganz/StyLua@0.18.2"
+lune = "lune-org/lune@0.8.8"