diff --git a/server-application-server/source/java/ch/ethz/sis/openbis/generic/server/xls/importer/helper/VocabularyImportHelper.java b/server-application-server/source/java/ch/ethz/sis/openbis/generic/server/xls/importer/helper/VocabularyImportHelper.java
index 5ac9dd9ba448bb3bb0a24e0ecc0a43492b7ca203..9e556c8bc2ba378ac41e31668a8bf2bdfa5a7fa6 100644
--- a/server-application-server/source/java/ch/ethz/sis/openbis/generic/server/xls/importer/helper/VocabularyImportHelper.java
+++ b/server-application-server/source/java/ch/ethz/sis/openbis/generic/server/xls/importer/helper/VocabularyImportHelper.java
@@ -79,7 +79,7 @@ public class VocabularyImportHelper extends BasicImportHelper
         String version = getValueByColumnName(header, values, Attribute.Version);
         String code = getValueByColumnName(header, values, Attribute.Code);
 
-        if (version == null) {
+        if (version == null || version.isEmpty()) {
             return true;
         } else {
             return VersionUtils.isNewVersion(version, VersionUtils.getStoredVersion(versions, ImportTypes.VOCABULARY_TYPE.getType(), code));
@@ -91,7 +91,7 @@ public class VocabularyImportHelper extends BasicImportHelper
         String version = getValueByColumnName(header, values, Attribute.Version);
         String code = getValueByColumnName(header, values, Attribute.Code);
 
-        if (version == null) {
+        if (version == null || version.isEmpty()) {
             Integer storedVersion = VersionUtils.getStoredVersion(versions, ImportTypes.VOCABULARY_TYPE.getType(), code);
             storedVersion++;
             version = storedVersion.toString();
diff --git a/server-application-server/source/java/ch/ethz/sis/openbis/generic/server/xls/importer/helper/VocabularyTermImportHelper.java b/server-application-server/source/java/ch/ethz/sis/openbis/generic/server/xls/importer/helper/VocabularyTermImportHelper.java
index c84fd86a683f549155cede35de2cdcdae86efc6e..745363fea27bc167457ef2310d64d4d83985fe65 100644
--- a/server-application-server/source/java/ch/ethz/sis/openbis/generic/server/xls/importer/helper/VocabularyTermImportHelper.java
+++ b/server-application-server/source/java/ch/ethz/sis/openbis/generic/server/xls/importer/helper/VocabularyTermImportHelper.java
@@ -91,7 +91,7 @@ public class VocabularyTermImportHelper extends BasicImportHelper
         String version = getValueByColumnName(header, values, Attribute.Version);
         String code = getValueByColumnName(header, values, Attribute.Code);
 
-        if (version == null) {
+        if (version == null || version.isEmpty()) {
             return true;
         } else {
             return VersionUtils.isNewVersion(version,
@@ -104,7 +104,7 @@ public class VocabularyTermImportHelper extends BasicImportHelper
         String version = getValueByColumnName(header, values, Attribute.Version);
         String code = getValueByColumnName(header, values, Attribute.Code);
 
-        if (version == null) {
+        if (version == null || version.isEmpty()) {
             Integer storedVersion = VersionUtils.getStoredVersion(versions, ImportTypes.VOCABULARY_TERM.getType() + "-" + vocabularyCode, code);
             storedVersion++;
             version = storedVersion.toString();