1 files changed, 1 insertions, 1 deletions
diff --git a/hash.h b/hash.h
index 059d1e2..3b2a984 100644
--- a/hash.h
+++ b/hash.h
@@ -2,7 +2,7 @@
 #define    HASH_H
 
 typedef uint32_t (*hash_func)(const void *key, size_t length);
-hash_func hash;
+extern hash_func hash;
 
 enum hashfunc_type {
     JENKINS_HASH=0, MURMUR3_HASH