diff --git a/internal/postprocessor/Dockerfile b/internal/postprocessor/Dockerfile
index e4aaa82587a3..0a606957c9b8 100644
--- a/internal/postprocessor/Dockerfile
+++ b/internal/postprocessor/Dockerfile
@@ -22,9 +22,10 @@ WORKDIR /postprocessor
 RUN CGO_ENABLED=0 GOOS=linux go build -v -o post_processor
 
 # Install tools used in build
-RUN GOTOOLCHAIN='auto' go install honnef.co/go/tools/cmd/staticcheck@latest && \
+RUN (export=GOTOOLCHAIN='auto' && \
+    go install honnef.co/go/tools/cmd/staticcheck@latest && \
     go install github.com/jstemmer/go-junit-report@latest && \
     go install golang.org/x/lint/golint@latest && \
-    go install golang.org/x/tools/cmd/goimports@latest
+    go install golang.org/x/tools/cmd/goimports@latest)
 
 CMD [ "/postprocessor/post_processor"]