diff --git a/docker/prebuild.sh b/docker/prebuild.sh
index 219aaa48e..e2f357cef 100755
--- a/docker/prebuild.sh
+++ b/docker/prebuild.sh
@@ -5,6 +5,7 @@
 for ARCH in arm x86 arm64 x86_64; do
   GOARCH=${ARCH}
   SDK=16
+  # The values here must correspond with those in ../syncthing/build-syncthing.py
   case ${ARCH} in
       arm)
         GCC="arm-linux-androideabi-clang"
@@ -19,6 +20,7 @@ for ARCH in arm x86 arm64 x86_64; do
         ;;
       x86_64)
         SDK=21
+        GOARCH=amd64
         GCC="x86_64-linux-android21-clang"
         ;;
       *)
diff --git a/syncthing/build-syncthing.py b/syncthing/build-syncthing.py
index c13ad1ad1..cac04fbdd 100644
--- a/syncthing/build-syncthing.py
+++ b/syncthing/build-syncthing.py
@@ -7,6 +7,7 @@
 
 SUPPORTED_PYTHON_PLATFORMS = ['Windows', 'Linux', 'Darwin']
 
+# The values here must correspond with those in ../docker/prebuild.sh
 BUILD_TARGETS = [
     {
         'arch': 'arm',