diff --git a/third_party/libwebp/BUILD.gn b/third_party/libwebp/BUILD.gn
index 82d85235a927..76cf79ee7695 100644
--- a/third_party/libwebp/BUILD.gn
+++ b/third_party/libwebp/BUILD.gn
@@ -33,7 +33,7 @@ if (skia_use_system_libwebp) {
       "../externals/libwebp/src",
       "../externals/libwebp",
     ]
-    configs += [ ":libwebp_defines" ]
+    configs = [ ":libwebp_defines" ]
     sources = [
       "../externals/libwebp/src/dsp/alpha_processing_sse41.c",
       "../externals/libwebp/src/dsp/dec_sse41.c",
@@ -60,7 +60,7 @@ if (skia_use_system_libwebp) {
       deps += [ "//third_party/cpu-features" ]
     }
 
-    configs += [ ":libwebp_defines" ]
+    configs = [ ":libwebp_defines" ]
     sources = [
       "../externals/libwebp/sharpyuv/sharpyuv.c",
       "../externals/libwebp/sharpyuv/sharpyuv_cpu.c",
@@ -171,6 +171,7 @@ if (skia_use_system_libwebp) {
       "../externals/libwebp/src/utils/filters_utils.c",
       "../externals/libwebp/src/utils/huffman_encode_utils.c",
       "../externals/libwebp/src/utils/huffman_utils.c",
+      "../externals/libwebp/src/utils/palette.c",
       "../externals/libwebp/src/utils/quant_levels_dec_utils.c",
       "../externals/libwebp/src/utils/quant_levels_utils.c",
       "../externals/libwebp/src/utils/random_utils.c",