diff --git a/scripts/cnode-helper-scripts/mithril.library b/scripts/cnode-helper-scripts/mithril.library
index abb3c174d..fe03ca8dd 100644
--- a/scripts/cnode-helper-scripts/mithril.library
+++ b/scripts/cnode-helper-scripts/mithril.library
@@ -128,7 +128,7 @@ read_optional_ips_from_input() {
 semantic_version_compare () {
     if [[ "${1}" == "${2}" ]]
     then
-        return 0
+        echo 0
     fi
     local IFS=.
     local i semantic_version1=($1) semantic_version2=($2)
@@ -141,14 +141,14 @@ semantic_version_compare () {
     do
         if ((10#${semantic_version1[i]:=0} > 10#${semantic_version2[i]:=0}))
         then
-            return 1
+            echo 1
         fi
         if ((10#${semantic_version1[i]} < 10#${semantic_version2[i]}))
         then
-            return 2
+            echo 2
         fi
     done
-    return 0
+    echo 0
 }
 
 set_defaults() {
@@ -198,8 +198,8 @@ check_mithril_upgrade_safe() {
   # Debug output
   echo "DEBUG: MITHRIL_MINIMUM_NODE_VERSION=${MITHRIL_MINIMUM_NODE_VERSION}"
 
-  semantic_version_compare "${NODE_CURRENT_VERSION}" "${MITHRIL_MINIMUM_NODE_VERSION}"
-  if [[ $? -lt 2 ]]; then
+  RC=$(semantic_version_compare "${NODE_CURRENT_VERSION}" "${MITHRIL_MINIMUM_NODE_VERSION}")
+  if [[ "${RC}" -lt 2 ]]; then
     # Node version is greater than or equal to the minimum required version for latest mithril release
     # Set MITHRIL_UPGRADE_SAFE to Y to allow mithril upgrade by scripts
     MITHRIL_UPGRADE_SAFE="Y"