diff --git a/modules/gplazma2-voms/src/main/java/org/dcache/gplazma/plugins/VomsPlugin.java b/modules/gplazma2-voms/src/main/java/org/dcache/gplazma/plugins/VomsPlugin.java
index 1affec17cde..e43e9456975 100644
--- a/modules/gplazma2-voms/src/main/java/org/dcache/gplazma/plugins/VomsPlugin.java
+++ b/modules/gplazma2-voms/src/main/java/org/dcache/gplazma/plugins/VomsPlugin.java
@@ -30,6 +30,7 @@
 import org.italiangrid.voms.store.VOMSTrustStore;
 import org.italiangrid.voms.store.VOMSTrustStores;
 import org.italiangrid.voms.util.CertificateValidatorBuilder;
+import org.italiangrid.voms.util.CertificateValidatorBuilder.OpensslHashFunction;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -70,6 +71,7 @@ public void start() {
               .lazyAnchorsLoading(false)
               .trustAnchorsUpdateInterval(trustAnchorsUpdateInterval)
               .trustAnchorsDir(caDir)
+              .opensslHashFunction(OpensslHashFunction.SHA1)
               .build();
         validator = VOMSValidators.newValidator(vomsTrustStore, certChainValidator);
     }