diff --git a/run b/run
index c565850..c916b4b 100755
--- a/run
+++ b/run
@@ -320,8 +320,8 @@ step12() {
   {
     pushd "../zig-$STEP12_"
     cp ../zig-$STEP11_/stage1/zig1.wasm stage1/zig1.wasm
-    fullbuild 15
-    build/stage3/bin/zig build --zig-lib-dir lib update-zig1
+    halfbuild 15
+    build/zig2 build --zig-lib-dir lib update-zig1
     popd
   }
 }
@@ -343,8 +343,9 @@ step13() {
   {
     pushd "../zig-$STEP13_"
     patch -p1 <"$HERE/0.10.0-1638-g7199d7c777-re-add-qualCast.patch"
-    ../zig-$STEP12_/build/stage3/bin/zig build --zig-lib-dir lib update-zig1
-    fullbuild 15
+    cp ../zig-$STEP12_/stage1/zig1.wasm stage1/zig1.wasm
+    halfbuild 15
+    build/zig2 build --zig-lib-dir lib update-zig1
     popd
   }
 }