diff --git a/16.0/Dockerfile b/16.0/Dockerfile
index 680d765..1cbf51d 100644
--- a/16.0/Dockerfile
+++ b/16.0/Dockerfile
@@ -36,9 +36,12 @@ RUN apt-get update && \
         python3-xlrd \
         python3-xlwt \
         xz-utils && \
+    if [ -z "${TARGETARCH}" ]; then \
+        TARGETARCH="$(dpkg --print-architecture)"; \
+    fi; \
     WKHTMLTOPDF_ARCH=${TARGETARCH} && \
     case ${TARGETARCH} in \
-    "amd64" | "") WKHTMLTOPDF_ARCH=amd64 && WKHTMLTOPDF_SHA=9df8dd7b1e99782f1cfa19aca665969bbd9cc159  ;; \
+    "amd64") WKHTMLTOPDF_ARCH=amd64 && WKHTMLTOPDF_SHA=9df8dd7b1e99782f1cfa19aca665969bbd9cc159  ;; \
     "arm64")  WKHTMLTOPDF_SHA=58c84db46b11ba0e14abb77a32324b1c257f1f22  ;; \
     "ppc64le") WKHTMLTOPDF_ARCH=ppc64el && WKHTMLTOPDF_SHA=7ed8f6dcedf5345a3dd4eeb58dc89704d862f9cd  ;; \
     esac \