diff --git a/pom.xml b/pom.xml
index 5c1c475..93bb283 100644
--- a/pom.xml
+++ b/pom.xml
@@ -9,7 +9,7 @@
     </parent>
     <groupId>fr.abes</groupId>
     <artifactId>sudoc</artifactId>
-    <version>1.0.1</version>
+    <version>1.0.2-SNAPSHOT</version>
     <packaging>jar</packaging>
     <name>sudoc</name>
     <description>webservices de récupération de ppns dans le sudoc</description>
diff --git a/src/main/java/fr/abes/sudoc/component/BaseXmlFunctionsCaller.java b/src/main/java/fr/abes/sudoc/component/BaseXmlFunctionsCaller.java
index 2153532..e863bea 100644
--- a/src/main/java/fr/abes/sudoc/component/BaseXmlFunctionsCaller.java
+++ b/src/main/java/fr/abes/sudoc/component/BaseXmlFunctionsCaller.java
@@ -49,7 +49,7 @@ public List<String> doiToPpn(String doi) throws UncategorizedSQLException {
         request.append("' and a.tag='017$a' ");
         request.append("and a.id in (select /*+ no_index(b BIBLIO_TABLE_FRBR_0XX_IDX_DATA) */ id from autorites.biblio_table_FRBR_0xx b where ");
         request.append("a.id=b.id and ");
-        request.append("b.tag='017$2' and SUBSTR(b.datas,1,50)='DOI' and a.POSFIELD=b.POSFIELD  and b.POSSUBFIELD='2')");
+        request.append("b.tag='017$2' and upper(SUBSTR(b.datas,1,50))='DOI' and a.POSFIELD=b.POSFIELD  and b.POSSUBFIELD='2')");
         return baseXmlJdbcTemplate.queryForList(request.toString(), String.class);
     }
 }