diff --git a/src/grib_accessor_classes_hash.c b/src/grib_accessor_classes_hash.c
index 9b275ff8b..aa46c1dfd 100644
--- a/src/grib_accessor_classes_hash.c
+++ b/src/grib_accessor_classes_hash.c
@@ -706,9 +706,10 @@ grib_accessor_classes_hash (const char *str, unsigned int len)
 
 #ifdef DEBUG
     {
+        const char *s;
         Assert( len <= MAX_WORD_LENGTH && len >= MIN_WORD_LENGTH );
         Assert( key <= MAX_HASH_VALUE && key >= 0 );
-        const char *s = classes[key].name;
+        s = classes[key].name;
         Assert( *str == *s && strcmp(str + 1, s + 1)==0 );
     }
 #endif