diff --git a/src/backend/access/common/reloptions.c b/src/backend/access/common/reloptions.c
index 599e160ca6..24211807ca 100644
--- a/src/backend/access/common/reloptions.c
+++ b/src/backend/access/common/reloptions.c
@@ -475,7 +475,7 @@ static relopt_real realRelOpts[] =
 };
 
 /* values from StdRdOptIndexCleanup */
-relopt_enum_elt_def StdRdOptIndexCleanupValues[] =
+static relopt_enum_elt_def StdRdOptIndexCleanupValues[] =
 {
 	{"auto", STDRD_OPTION_VACUUM_INDEX_CLEANUP_AUTO},
 	{"on", STDRD_OPTION_VACUUM_INDEX_CLEANUP_ON},
@@ -490,7 +490,7 @@ relopt_enum_elt_def StdRdOptIndexCleanupValues[] =
 };
 
 /* values from GistOptBufferingMode */
-relopt_enum_elt_def gistBufferingOptValues[] =
+static relopt_enum_elt_def gistBufferingOptValues[] =
 {
 	{"auto", GIST_OPTION_BUFFERING_AUTO},
 	{"on", GIST_OPTION_BUFFERING_ON},
@@ -499,7 +499,7 @@ relopt_enum_elt_def gistBufferingOptValues[] =
 };
 
 /* values from ViewOptCheckOption */
-relopt_enum_elt_def viewCheckOptValues[] =
+static relopt_enum_elt_def viewCheckOptValues[] =
 {
 	/* no value for NOT_SET */
 	{"local", VIEW_OPTION_CHECK_OPTION_LOCAL},
diff --git a/src/backend/access/transam/commit_ts.c b/src/backend/access/transam/commit_ts.c
index 20950eb1e4..4dc8d402bd 100644
--- a/src/backend/access/transam/commit_ts.c
+++ b/src/backend/access/transam/commit_ts.c
@@ -98,7 +98,7 @@ typedef struct CommitTimestampShared
 	bool		commitTsActive;
 } CommitTimestampShared;
 
-CommitTimestampShared *commitTsShared;
+static CommitTimestampShared *commitTsShared;
 
 
 /* GUC variable */
diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c
index 53f3e7fd1a..47d80b0d25 100644
--- a/src/backend/access/transam/xact.c
+++ b/src/backend/access/transam/xact.c
@@ -121,9 +121,9 @@ bool		bsysscan = false;
  * The XIDs are stored sorted in numerical order (not logical order) to make
  * lookups as fast as possible.
  */
-FullTransactionId XactTopFullTransactionId = {InvalidTransactionId};
-int			nParallelCurrentXids = 0;
-TransactionId *ParallelCurrentXids;
+static FullTransactionId XactTopFullTransactionId = {InvalidTransactionId};
+static int nParallelCurrentXids = 0;
+static TransactionId *ParallelCurrentXids;
 
 /*
  * Miscellaneous flag bits to record events which occur on the top level
diff --git a/src/backend/catalog/storage.c b/src/backend/catalog/storage.c
index cd31e68e95..c06e414a38 100644
--- a/src/backend/catalog/storage.c
+++ b/src/backend/catalog/storage.c
@@ -73,7 +73,7 @@ typedef struct PendingRelSync
 } PendingRelSync;
 
 static PendingRelDelete *pendingDeletes = NULL; /* head of linked list */
-HTAB	   *pendingSyncHash = NULL;
+static HTAB *pendingSyncHash = NULL;
 
 
 /*
diff --git a/src/backend/replication/logical/launcher.c b/src/backend/replication/logical/launcher.c
index 6a4b2d4306..eabcc1bcba 100644
--- a/src/backend/replication/logical/launcher.c
+++ b/src/backend/replication/logical/launcher.c
@@ -65,7 +65,7 @@ typedef struct LogicalRepCtxStruct
 	LogicalRepWorker workers[FLEXIBLE_ARRAY_MEMBER];
 } LogicalRepCtxStruct;
 
-LogicalRepCtxStruct *LogicalRepCtx;
+static LogicalRepCtxStruct *LogicalRepCtx;
 
 static void ApplyLauncherWakeup(void);
 static void logicalrep_launcher_onexit(int code, Datum arg);
diff --git a/src/backend/replication/logical/tablesync.c b/src/backend/replication/logical/tablesync.c
index 61aee61b8e..b03e0f5aac 100644
--- a/src/backend/replication/logical/tablesync.c
+++ b/src/backend/replication/logical/tablesync.c
@@ -124,7 +124,7 @@ static bool table_states_valid = false;
 static List *table_states_not_ready = NIL;
 static bool FetchTableStates(bool *started_tx);
 
-StringInfo	copybuf = NULL;
+static StringInfo copybuf = NULL;
 
 /*
  * Exit routine for synchronization worker.
diff --git a/src/backend/replication/logical/worker.c b/src/backend/replication/logical/worker.c
index 725a21b55e..3b80ed92c0 100644
--- a/src/backend/replication/logical/worker.c
+++ b/src/backend/replication/logical/worker.c
@@ -251,7 +251,7 @@ static MemoryContext LogicalStreamingContext = NULL;
 WalReceiverConn *LogRepWorkerWalRcvConn = NULL;
 
 Subscription *MySubscription = NULL;
-bool		MySubscriptionValid = false;
+static bool MySubscriptionValid = false;
 
 bool		in_remote_transaction = false;
 static XLogRecPtr remote_final_lsn = InvalidXLogRecPtr;
diff --git a/src/backend/tcop/cmdtag.c b/src/backend/tcop/cmdtag.c
index a83bab14f4..262484f561 100644
--- a/src/backend/tcop/cmdtag.c
+++ b/src/backend/tcop/cmdtag.c
@@ -28,7 +28,7 @@ typedef struct CommandTagBehavior
 #define PG_CMDTAG(tag, name, evtrgok, rwrok, rowcnt) \
 	{ name, evtrgok, rwrok, rowcnt },
 
-const CommandTagBehavior tag_behavior[COMMAND_TAG_NEXTTAG] = {
+static const CommandTagBehavior tag_behavior[COMMAND_TAG_NEXTTAG] = {
 #include "tcop/cmdtaglist.h"
 };