diff --git a/thrift/compiler/sema/patch_mutator.cc b/thrift/compiler/sema/patch_mutator.cc
index cfc1c04231a..cf57951bb01 100644
--- a/thrift/compiler/sema/patch_mutator.cc
+++ b/thrift/compiler/sema/patch_mutator.cc
@@ -80,6 +80,10 @@ const char* getOptionalPatchTypeName(t_base_type::type base_type) {
   }
 }
 
+std::string getSibName(const std::string& sibling, const std::string& name) {
+  return sibling.substr(0, sibling.find_last_of("/")) + name;
+}
+
 // A fluent function to set the doc string on a given node.
 template <typename N>
 N& doc(std::string txt, N& node) {
@@ -377,18 +381,54 @@ t_type_ref patch_generator::find_patch_type(
       os << "Could not find expected patch type: " << name;
     });
     return {};
-  } else if (auto* structured = dynamic_cast<const t_structured*>(type)) {
-    // Try to find the generated patch type.
+  }
+
+  // Check the field for a custom patch type.
+  if (auto* custom = field.find_annotation_or_null("thrift.patch.uri")) {
+    if (const auto* result =
+            dynamic_cast<const t_type*>(program_.scope()->find_def(*custom))) {
+      return t_type_ref::from_ptr(result);
+    }
+    ctx_.warning(field, "Could not find custom type: {}", *custom);
+  }
+
+  // Check the field type for a custom patch type.
+  if (auto* custom = t_typedef::get_first_annotation_or_null(
+          field.type().get_type(), {"thrift.patch.uri"})) {
+    if (const auto* result =
+            dynamic_cast<const t_type*>(program_.scope()->find_def(*custom))) {
+      return t_type_ref::from_ptr(result);
+    }
+    ctx_.warning(*field.type(), "Could not find custom type: {}", *custom);
+  }
+
+  if (auto* structured = dynamic_cast<const t_structured*>(type)) {
     std::string name = structured->name() + "ValuePatch";
     if (field.qualifier() == t_field_qualifier::optional) {
       name = "Optional" + std::move(name);
     }
-    // It should be in the same program as the type itself.
+
+    if (!structured->uri().empty()) { // Try to look up by URI.
+      if (auto* result = dynamic_cast<const t_type*>(program_.scope()->find_def(
+              getSibName(structured->uri(), name)))) {
+        return t_type_ref::from_ptr(result);
+      }
+    }
+
+    // Try to look up by Name.
+    // Look for it in the same program as the type itself.
     t_type_ref result = program_.scope()->ref_type(
         *structured->program(), name, field.src_range());
     if (auto* ph = result.get_unresolved_type()) {
+      // Try the current program.
+      t_type_ref fallback =
+          program_.scope()->ref_type(program_, name, field.src_range());
+      if (fallback.resolved()) {
+        return fallback; // TODO(afuller): Remove support for local fallbacks.
+      }
       // Set the location info, in case the type can't be resolved later.
       ph->set_lineno(field.lineno());
+      ph->set_src_range(field.src_range());
       ph->set_generated();
     }
     return result;