diff --git a/Dockerfile b/Dockerfile
index d396b18..155af14 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM alpine:3.17.1
+FROM alpine:3.19.0
 
 RUN apk add make g++
 
@@ -17,6 +17,6 @@ RUN chown -R saundersp /home/saundersp/sorting_algorithms
 
 USER saundersp
 
-RUN make -j $NPROC
+RUN make -j $(nproc)
 
 ENTRYPOINT ["bin/data"]