diff --git a/packages/compiler/src/compiler/codegen.ts b/packages/compiler/src/compiler/codegen.ts
index 847368c..0e278b4 100644
--- a/packages/compiler/src/compiler/codegen.ts
+++ b/packages/compiler/src/compiler/codegen.ts
@@ -83,7 +83,7 @@ function stringifyId(i: Identifier): Items {
     return [ { ... i, type: TokenType.STRING, text: JSON.stringify(i.text) } ];
 }
 
-function binderTypeGuard(ctx: ExpansionContext, t: TemplateFunction): (binder: Binder, index: number) => Items {
+function binderTypeGuard(t: TemplateFunction): (binder: Binder, index: number) => Items {
     return (binder, index) => {
         if (binder.id.text[0] === '_') {
             return t`${`/* Ignoring underscore-prefixed binder ${binder.id.text} */`}`;
@@ -103,10 +103,12 @@ function binderTypeGuard(ctx: ExpansionContext, t: TemplateFunction): (binder: B
                     return t`if (typeof (${raw}) !== ${JSON.stringify(typeText)}) return;\n${bind}`;
                 case 'any':
                     return bind;
-                default:
-                    ctx.emitError(`Cannot emit guard for binding of type: ${JSON.stringify(typeText)}`,
-                                  getRange(binder.type));
-                    return bind; /* act as if "any", for now */
+                default: {
+                    const intermediate = t`__v_${''+index}`;
+                    return t`const ${intermediate} = ${binder.type}.__from_preserve__(${raw});
+                             if (${intermediate} === void 0) return;
+                             const ${[binder.id]} = ${intermediate};`;
+                }
             }
         }
     };
@@ -158,7 +160,7 @@ export function expand(tree: Items, ctx: ExpansionContext): Items {
             observer: __SYNDICATE__.Turn.ref(__SYNDICATE__.assertionFacetObserver(
                 (${ctx.argDecl(t, '__vs', '__SYNDICATE__.AnyValue')}) => {
                     if (Array.isArray(__vs)) {
-${joinItems(sa.captureBinders.map(binderTypeGuard(ctx, t)), '\n')}
+${joinItems(sa.captureBinders.map(binderTypeGuard(t)), '\n')}
                         ${body}
                     }
                 }
@@ -231,7 +233,7 @@ ${joinItems(sa.captureBinders.map(binderTypeGuard(ctx, t)), '\n')}
 
         const sa = compilePattern(s.pattern);
         const guardBody = (body: Statement) => t`if (Array.isArray(__vs)) {
-${joinItems(sa.captureBinders.map(binderTypeGuard(ctx, t)), '\n')}
+${joinItems(sa.captureBinders.map(binderTypeGuard(t)), '\n')}
             ${body}
         }`;
 
diff --git a/packages/core/src/runtime/quasivalue.ts b/packages/core/src/runtime/quasivalue.ts
index c598101..488dbe8 100644
--- a/packages/core/src/runtime/quasivalue.ts
+++ b/packages/core/src/runtime/quasivalue.ts
@@ -4,18 +4,12 @@
 import { AnyValue, Ref } from './actor.js';
 import { Pattern, toPattern } from '../gen/dataspacePatterns.js';
 import * as P from './pattern.js';
-import { Value, RecordConstructorInfo, is, Record } from '@preserves/core';
-import { Meta, Type, GenType } from '@preserves/schema';
-
-export type DefinitionOrVariantInfo = {
-    schema: Value,
-    imports: unknown,
-    definitionName: symbol,
-};
+import { RecordConstructorInfo, is, Record } from '@preserves/core';
+import { Meta, Type, GenType, SchemaDefinition } from '@preserves/schema';
 
 export type QuasiValueConstructorInfo =
     | { constructorInfo: RecordConstructorInfo<AnyValue, Ref> }
-    | { schema(): DefinitionOrVariantInfo }
+    | { schema(): SchemaDefinition }
     | { quasiValue(... args: QuasiValue[]): QuasiValue }
 ;