diff --git a/scripts/circle/compare_reqs.sh b/scripts/circle/compare_reqs.sh
index 5c6fa0a71..d02c73642 100755
--- a/scripts/circle/compare_reqs.sh
+++ b/scripts/circle/compare_reqs.sh
@@ -2,10 +2,11 @@
 
 set -e
 
-# update lock and build requirements files
-yes | ./scripts/dependencies/relock_dependencies.sh circle-requirements
+# Update lock and build requirements files.
+# Use option -k to keep the Pipfile.lock file, so the process is deterministic with respect to that file.
+yes | ./scripts/dependencies/relock_dependencies.sh -k circle-requirements
 
-echo "---- validating requirements.txt ----"
+echo "---- Validating requirements.txt ----"
 REQSHASH=$(md5sum requirements.txt | cut -d ' ' -f1)
 TESTHASH=$(md5sum circle-requirements.txt | cut -d ' ' -f1)
 
@@ -13,7 +14,6 @@ echo "- $REQSHASH"
 echo "- $TESTHASH"
 if [ $REQSHASH == $TESTHASH ]; then
     echo "- requirements.txt is valid ...."
-
 else
     echo "- requirements.txt contains inconsistencies ...."
     echo "- you may want to run `pipenv sync --dev` and then ./scripts/dependencies/relock_dependencies.sh ...."
@@ -22,7 +22,7 @@ else
     exit 2
 fi
 
-echo "---- validating dev-requirements.txt ----"
+echo "---- Validating dev-requirements.txt ----"
 REQSHASH=$(md5sum dev-requirements.txt | cut -d ' ' -f1)
 TESTHASH=$(md5sum dev-circle-requirements.txt | cut -d ' ' -f1)
 
@@ -31,7 +31,6 @@ echo "- $TESTHASH"
 
 if [ $REQSHASH == $TESTHASH ]; then
     echo "- dev-requirements.txt is valid ...."
-
 else
     echo "- dev-requirements.txt contains inconsistencies ...."
     echo "- you may want to run `pipenv sync --dev` and then ./scripts/dependencies/relock_dependencies.sh ...."
diff --git a/scripts/dependencies/relock_dependencies.sh b/scripts/dependencies/relock_dependencies.sh
index f1a97ec69..ef8d4351f 100755
--- a/scripts/dependencies/relock_dependencies.sh
+++ b/scripts/dependencies/relock_dependencies.sh
@@ -1,17 +1,33 @@
 #!/usr/bin/env bash
 
+# Parse optional flag -k, to be used when we want to base the process on an existing Pipfile.lock
+KEEP_LOCK=false
+OPTIND=1
+while getopts 'k' opt; do
+    case $opt in
+        k) KEEP_LOCK=true ;;
+        *) echo 'Error in command line parsing' >&2
+           exit 1
+    esac
+done
+shift "$(( OPTIND - 1 ))"
+
 # can change output file names with relock_dependencies.sh <prefix>
 PREFIX=${1:-requirements}
 
 # these steps might fail, but that's okay.
-echo "Removing existing lock files..."
+if ! "$KEEP_LOCK"; then
+    echo "Removing existing Pipfile.lock file"
+    rm -f Pipfile.lock
+fi
+
+echo "Removing existing requirement files"
 pipenv --rm
-rm -f Pipfile.lock
 rm -f $PREFIX.txt
 rm -f dev-$PREFIX.txt
 rm -f docs-$PREFIX.txt
 
-echo "Removing pip and pipenv system cache..."
+echo "Removing pip and pipenv system cache"
 rm -r ~/.cache/pip ~/.cache/pipenv
 
 # start enforcing failures