diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index 5f1af911b7..83b3750b0d 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -1846,7 +1846,7 @@ virDomainDiskEmptySource(virDomainDiskDefPtr def)
 
 
 const char *
-virDomainDiskGetDriver(virDomainDiskDefPtr def)
+virDomainDiskGetDriver(const virDomainDiskDef *def)
 {
     return def->src->driverName;
 }
diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h
index 122a051b2a..99355532f3 100644
--- a/src/conf/domain_conf.h
+++ b/src/conf/domain_conf.h
@@ -2765,7 +2765,7 @@ const char *virDomainDiskGetSource(virDomainDiskDef const *def);
 int virDomainDiskSetSource(virDomainDiskDefPtr def, const char *src)
     ATTRIBUTE_RETURN_CHECK;
 void virDomainDiskEmptySource(virDomainDiskDefPtr def);
-const char *virDomainDiskGetDriver(virDomainDiskDefPtr def);
+const char *virDomainDiskGetDriver(const virDomainDiskDef *def);
 int virDomainDiskSetDriver(virDomainDiskDefPtr def, const char *name)
     ATTRIBUTE_RETURN_CHECK;
 int virDomainDiskGetFormat(virDomainDiskDefPtr def);