diff --git a/spec/lang/declaration/local_type_spec.lua b/spec/lang/declaration/local_type_spec.lua
index f65c17cd..3f048d1e 100644
--- a/spec/lang/declaration/local_type_spec.lua
+++ b/spec/lang/declaration/local_type_spec.lua
@@ -231,4 +231,16 @@ describe("local type", function()
    ]], {
       { y = 14, msg = 'in record field: Data: string "invalid" is not a member of MyEnum' }
    }))
+
+   it("does not accept a built-in simple type followed by a dotted name (regression test for #1136)", util.check_type_error([[
+      local a: number.x.y.z = 1
+      local b: string.a.b = "x"
+      local c: integer.foo = 1
+      local d: boolean.foo = true
+   ]], {
+      { y = 1, msg = "unknown type number.x.y.z" },
+      { y = 2, msg = "unknown type string.a.b" },
+      { y = 3, msg = "unknown type integer.foo" },
+      { y = 4, msg = "unknown type boolean.foo" },
+   }))
 end)
diff --git a/teal.lua b/teal.lua
index 3e56bbc4..b97d34bd 100644
--- a/teal.lua
+++ b/teal.lua
@@ -1971,7 +1971,12 @@ end
 parse_simple_type_or_nominal = function(state, block)
    local tk = block.tk
    local st = simple_types[tk]
-   if st then
+
+
+
+
+   local rest = block[reader.BLOCK_INDEXES.NOMINAL_TYPE.NAME + 1]
+   if st and not (rest and rest.kind == "identifier") then
       return new_type(state, block, tk)
    elseif tk == "table" and block.kind ~= "nominal_type" then
       local typ = new_type(state, block, "map")
diff --git a/teal/ast.lua b/teal/ast.lua
index ffef498b..ed3105f0 100644
--- a/teal/ast.lua
+++ b/teal/ast.lua
@@ -1969,7 +1969,12 @@ end
 parse_simple_type_or_nominal = function(state, block)
    local tk = block.tk
    local st = simple_types[tk]
-   if st then
+
+
+
+
+   local rest = block[reader.BLOCK_INDEXES.NOMINAL_TYPE.NAME + 1]
+   if st and not (rest and rest.kind == "identifier") then
       return new_type(state, block, tk)
    elseif tk == "table" and block.kind ~= "nominal_type" then
       local typ = new_type(state, block, "map")
diff --git a/teal/ast.tl b/teal/ast.tl
index 65306fb6..6bb0e65a 100644
--- a/teal/ast.tl
+++ b/teal/ast.tl
@@ -1969,7 +1969,12 @@ end
 parse_simple_type_or_nominal = function(state: ParseState, block: Block): FirstOrderType
    local tk = block.tk
    local st = simple_types[tk as TypeName]
-   if st then
+   -- Only short-circuit to the built-in simple type when there is no trailing
+   -- dotted name part. Otherwise fall through to the nominal path below so that
+   -- an invalid annotation like `number.x.y.z` is reported as an unknown type
+   -- instead of being silently accepted as `number` (issue #1136).
+   local rest = block[reader.BLOCK_INDEXES.NOMINAL_TYPE.NAME + 1]
+   if st and not (rest and rest.kind == "identifier") then
       return new_type(state, block, tk as TypeName) as StructuralType
    elseif tk == "table" and block.kind ~= "nominal_type" then -- reader already turns plain `table` into map_type
       local typ = new_type(state, block, "map") as MapType
diff --git a/tl.lua b/tl.lua
index caf916c2..b90777b6 100644
--- a/tl.lua
+++ b/tl.lua
@@ -2225,7 +2225,12 @@ end
 parse_simple_type_or_nominal = function(state, block)
    local tk = block.tk
    local st = simple_types[tk]
-   if st then
+
+
+
+
+   local rest = block[reader.BLOCK_INDEXES.NOMINAL_TYPE.NAME + 1]
+   if st and not (rest and rest.kind == "identifier") then
       return new_type(state, block, tk)
    elseif tk == "table" and block.kind ~= "nominal_type" then
       local typ = new_type(state, block, "map")