diff --git a/src/ivfflat.h b/src/ivfflat.h
index 46c2111..a72a3ab 100644
--- a/src/ivfflat.h
+++ b/src/ivfflat.h
@@ -3,6 +3,10 @@
 
 #include "postgres.h"
 
+#if PG_VERSION_NUM < 100000
+#error "Requires PostgreSQL 10+"
+#endif
+
 #include "access/generic_xlog.h"
 #include "access/reloptions.h"
 #include "nodes/execnodes.h"
@@ -19,10 +23,6 @@
 #include "portability/instr_time.h"
 #endif
 
-#if PG_VERSION_NUM < 100000
-#error "Requires PostgreSQL 10+"
-#endif
-
 /* Support functions */
 #define IVFFLAT_DISTANCE_PROC 1
 #define IVFFLAT_NORM_PROC 2