diff --git a/fpdfsdk/BUILD.gn b/fpdfsdk/BUILD.gn
index 081152e..93cfe5c 100644
--- a/fpdfsdk/BUILD.gn
+++ b/fpdfsdk/BUILD.gn
@@ -62,6 +62,7 @@
     "fpdf_progressive.cpp",
     "fpdf_save.cpp",
     "fpdf_searchex.cpp",
+    "fpdf_signature.cpp",
     "fpdf_structtree.cpp",
     "fpdf_sysfontinfo.cpp",
     "fpdf_text.cpp",
@@ -145,6 +146,7 @@
     "fpdf_ppo_embeddertest.cpp",
     "fpdf_save_embeddertest.cpp",
     "fpdf_searchex_embeddertest.cpp",
+    "fpdf_signature_embeddertest.cpp",
     "fpdf_structtree_embeddertest.cpp",
     "fpdf_sysfontinfo_embeddertest.cpp",
     "fpdf_text_embeddertest.cpp",