diff --git a/.docker/Dockerfile b/.docker/Dockerfile
index 39565e6..3a24f3e 100644
--- a/.docker/Dockerfile
+++ b/.docker/Dockerfile
@@ -6,7 +6,7 @@ RUN getuto
 
 RUN emerge-webrsync
 
-RUN emerge \
+RUN emerge --jobs=$(nproc) \
     =dev-lang/rust-bin-9999 \
     llvm-core/clang \
     llvm-core/lld \