diff --git a/src/include/miscadmin.h b/src/include/miscadmin.h
index e099b91014f..8ccdf61246b 100644
--- a/src/include/miscadmin.h
+++ b/src/include/miscadmin.h
@@ -319,7 +319,7 @@ extern void PreventCommandDuringRecovery(const char *cmdname);
  * access shared catalogs, as a safety check.  This is checked by genam.c when
  * a catalog scan takes place to verify that no shared catalogs are accessed.
  */
-extern bool accessSharedCatalogsInDecoding;
+extern PGDLLIMPORT bool accessSharedCatalogsInDecoding;
 
 /*****************************************************************************
  *	  pdir.h --																 *
diff --git a/src/include/portability/instr_time.h b/src/include/portability/instr_time.h
index a398c028215..92558e234ac 100644
--- a/src/include/portability/instr_time.h
+++ b/src/include/portability/instr_time.h
@@ -129,7 +129,7 @@ typedef enum
 #endif
 } TimingClockSourceType;
 
-extern int	timing_clock_source;
+extern PGDLLIMPORT int timing_clock_source;
 
 /*
  * Initialize timing infrastructure