diff --git a/docker/dev/Dockerfile b/docker/dev/Dockerfile
index 4ee54eeeb4..e36ea5699d 100644
--- a/docker/dev/Dockerfile
+++ b/docker/dev/Dockerfile
@@ -110,8 +110,10 @@ COPY ./docker/dev/init_hook.sh /usr/bin/
 # handle differences in vpp.conf which are between supported VPP versions
 ARG VPP_VERSION
 COPY ./docker/dev/legacy-nat.conf /tmp/legacy-nat.conf
-RUN bash -c "if [[ \"$VPP_VERSION\" < "2101" ]]; then cat /tmp/legacy-nat.conf >> /etc/vpp/vpp.conf; fi"
-RUN rm /tmp/legacy-nat.conf
+RUN if [[ "$VPP_VERSION" < "2009" ]]; then \
+		cat /tmp/legacy-nat.conf >> /etc/vpp/vpp.conf; \
+	fi; \
+	rm /tmp/legacy-nat.conf
 
 # Install agent
 WORKDIR /src/ligato/vpp-agent
diff --git a/docker/prod/Dockerfile b/docker/prod/Dockerfile
index 244ad4a2c7..8e5874daeb 100644
--- a/docker/prod/Dockerfile
+++ b/docker/prod/Dockerfile
@@ -42,8 +42,10 @@ COPY init_hook.sh /usr/bin/
 # handle differences in vpp.conf which are between supported VPP versions
 ARG VPP_VERSION
 COPY legacy-nat.conf /tmp/legacy-nat.conf
-RUN bash -c "if [[ \"$VPP_VERSION\" < "2101" ]]; then cat /tmp/legacy-nat.conf >> /etc/vpp/vpp.conf; fi"
-RUN rm /tmp/legacy-nat.conf
+RUN if [[ "$VPP_VERSION" < "2009" ]]; then \
+		cat /tmp/legacy-nat.conf >> /etc/vpp/vpp.conf; \
+	fi; \
+	rm /tmp/legacy-nat.conf
 
 # Install agent
 COPY --from=devimg \