diff --git a/packages/core/src/Theorem.ts b/packages/core/src/Theorem.ts
index 55010bca..89571d91 100644
--- a/packages/core/src/Theorem.ts
+++ b/packages/core/src/Theorem.ts
@@ -1,6 +1,7 @@
 import { z } from 'zod'
+import { Ref } from './Ref.js'
 import { recordSchema } from './Record.js'
-import { formulaSchema } from './Formula.js'
+import { Formula, formulaSchema } from './Formula.js'
 
 export const theoremSchema = z.intersection(
   z.object({
@@ -12,3 +13,12 @@ export const theoremSchema = z.intersection(
 )
 
 export type Theorem = z.infer<typeof theoremSchema>
+
+// TODO: everything below this line was pushed down and should still be unified
+export type SerializedTheorem = {
+  id: number
+  when: Formula<number>
+  then: Formula<number>
+  description: string
+  refs: Ref[]
+}
diff --git a/packages/core/src/index.ts b/packages/core/src/index.ts
index 3ed58d42..3e845850 100644
--- a/packages/core/src/index.ts
+++ b/packages/core/src/index.ts
@@ -15,7 +15,7 @@ export {
   proveTheorem,
 } from './Logic/index.js'
 export { type Space, SpacePage } from './Space.js'
-export { type Theorem } from './Theorem.js'
+export { type Theorem, SerializedTheorem } from './Theorem.js'
 export { type Trait } from './Trait.js'
 export { type Version } from './Bundle.js'
 
diff --git a/packages/viewer/src/__test__/factories.ts b/packages/viewer/src/__test__/factories.ts
index adac7f60..974f5b2b 100644
--- a/packages/viewer/src/__test__/factories.ts
+++ b/packages/viewer/src/__test__/factories.ts
@@ -1,10 +1,9 @@
-import { TestUtils } from '@pi-base/core'
+import { type SerializedTheorem, TestUtils } from '@pi-base/core'
 
 import {
   type AssertedTrait,
   Collection,
   type Property,
-  type SerializedTheorem,
   type Space,
   type Trait,
   Traits,
diff --git a/packages/viewer/src/gateway.ts b/packages/viewer/src/gateway.ts
index 2e2d7db1..5303e474 100644
--- a/packages/viewer/src/gateway.ts
+++ b/packages/viewer/src/gateway.ts
@@ -1,12 +1,6 @@
 import * as pb from '@pi-base/core'
 
-import {
-  Id,
-  type Property,
-  type Space,
-  type SerializedTheorem,
-  type Trait,
-} from './models'
+import { Id, type Property, type Space, type Trait } from './models'
 import { trace } from './debug'
 
 export type Sync = (
@@ -18,7 +12,7 @@ export type Sync = (
 export type Result = {
   spaces: Space[]
   properties: Property[]
-  theorems: SerializedTheorem[]
+  theorems: pb.SerializedTheorem[]
   traits: Trait[]
   etag: string
   sha: string
@@ -90,7 +84,7 @@ function theorem({
   then,
   description,
   refs,
-}: pb.Theorem): SerializedTheorem {
+}: pb.Theorem): pb.SerializedTheorem {
   return {
     id: Id.toInt(uid),
     when: pb.formula.mapProperty(Id.toInt, when),
diff --git a/packages/viewer/src/models/Theorem.ts b/packages/viewer/src/models/Theorem.ts
index 47f00db9..d3f3e4c9 100644
--- a/packages/viewer/src/models/Theorem.ts
+++ b/packages/viewer/src/models/Theorem.ts
@@ -1,6 +1,6 @@
-import { formula as F } from '@pi-base/core'
+import { formula as F, type SerializedTheorem } from '@pi-base/core'
 
-import type { Property, Ref, SerializedTheorem } from '@/models'
+import type { Property, Ref } from '@/models'
 
 export default class Theorem {
   static hydrate(
diff --git a/packages/viewer/src/models/Theorems.ts b/packages/viewer/src/models/Theorems.ts
index 9b242538..0dea65bc 100644
--- a/packages/viewer/src/models/Theorems.ts
+++ b/packages/viewer/src/models/Theorems.ts
@@ -1,8 +1,8 @@
-import { formula as F } from '@pi-base/core'
+import { formula as F, type SerializedTheorem } from '@pi-base/core'
 
 import Collection from './Collection'
 import { default as Theorem } from './Theorem'
-import type { Property, SerializedTheorem } from '@/types'
+import type { Property } from '@/types'
 
 export default class Theorems {
   static build(
diff --git a/packages/viewer/src/stores/index.ts b/packages/viewer/src/stores/index.ts
index 60ecd34b..2fb5c2a1 100644
--- a/packages/viewer/src/stores/index.ts
+++ b/packages/viewer/src/stores/index.ts
@@ -1,10 +1,10 @@
+import { type SerializedTheorem } from '@pi-base/core'
 import type * as Gateway from '@/gateway'
 import {
   Collection,
   Theorems,
   Traits,
   type Property,
-  type SerializedTheorem,
   type Space,
   type Trait,
 } from '@/models'
diff --git a/packages/viewer/src/types/index.ts b/packages/viewer/src/types/index.ts
index b41724f0..d60a0123 100644
--- a/packages/viewer/src/types/index.ts
+++ b/packages/viewer/src/types/index.ts
@@ -41,14 +41,6 @@ export type DeducedTrait = {
 
 export type Trait = AssertedTrait | DeducedTrait
 
-export type SerializedTheorem = {
-  id: number
-  when: Formula<number>
-  then: Formula<number>
-  description: string
-  refs: Ref[]
-}
-
 export type SerializedProof = {
   properties: number[]
   theorems: number[]