diff --git a/src/include/distributed/citus_nodes.h b/src/include/distributed/citus_nodes.h
index 27fc8d7b0..c593f48f5 100644
--- a/src/include/distributed/citus_nodes.h
+++ b/src/include/distributed/citus_nodes.h
@@ -70,7 +70,7 @@ typedef enum CitusNodeTag
 } CitusNodeTag;
 
 
-const char** CitusNodeTagNames;
+extern const char** CitusNodeTagNames;
 
 
 typedef struct CitusNode