diff --git a/Package.swift b/Package.swift
index bb10f18db..eac4647dd 100644
--- a/Package.swift
+++ b/Package.swift
@@ -47,7 +47,10 @@ let package = Package(
             "case_fold_switch.inc",
             "entities.inc",
           ],
-          cSettings: cSettings
+          cSettings: cSettings,
+          linkerSettings: [
+              .linkedLibrary("pthread", .when(platforms: [.linux])),
+          ]
         ),
         .target(name: "cmark-gfm-extensions",
           dependencies: [
diff --git a/src/include/module.modulemap b/src/include/module.modulemap
index 1fc033abb..e59f0c196 100644
--- a/src/include/module.modulemap
+++ b/src/include/module.modulemap
@@ -1,4 +1,4 @@
-module cmark_gfm {
+module cmark_gfm [extern_c] {
     umbrella header "cmark-gfm.h"
     header "cmark-gfm_config.h"
     header "cmark-gfm-extension_api.h"