diff --git a/CMakeLists.txt b/CMakeLists.txt
index 65115fbf15b..2753b821b8b 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -54,6 +54,7 @@ if(FIND_PM_DEPS)
   find_package(ArgumentParser CONFIG REQUIRED)
   find_package(SwiftDriver CONFIG REQUIRED)
   find_package(SwiftCollections CONFIG REQUIRED)
+  find_package(SwiftASN1 CONFIG REQUIRED)
   find_package(SwiftCertificates CONFIG REQUIRED)
   find_package(SwiftCrypto CONFIG REQUIRED)
 endif()
diff --git a/Sources/PackageSigning/CMakeLists.txt b/Sources/PackageSigning/CMakeLists.txt
index 881d983cd91..941ca822629 100644
--- a/Sources/PackageSigning/CMakeLists.txt
+++ b/Sources/PackageSigning/CMakeLists.txt
@@ -16,7 +16,8 @@ add_library(PackageSigning STATIC
 target_link_libraries(PackageSigning PUBLIC
   $<$<NOT:$<PLATFORM_ID:Darwin>>:Foundation>
   Basics
-  # Crypto ## TODO: uncomment once we resolve build problems
+  Crypto
+  X509
   PackageModel
   TSCBasic
   TSCUtility)
diff --git a/Sources/PackageSigning/SignatureProvider.swift b/Sources/PackageSigning/SignatureProvider.swift
index dfd8a35f974..b69b3fbb74c 100644
--- a/Sources/PackageSigning/SignatureProvider.swift
+++ b/Sources/PackageSigning/SignatureProvider.swift
@@ -19,6 +19,7 @@ import CryptoKit // TODO: remove when we can import Crypto
 
 import Basics
 //import Crypto
+@_implementationOnly import X509
 
 public enum SignatureProvider {
     public static func sign(