diff --git a/contrib/pageinspect/btreefuncs.c b/contrib/pageinspect/btreefuncs.c
index 97c5ae409a4b0b4db20e82cb527d65700c8552cf..f02c3821834cbd72079a0dc7eb033a5c8d9b1672 100644
--- a/contrib/pageinspect/btreefuncs.c
+++ b/contrib/pageinspect/btreefuncs.c
@@ -57,12 +57,13 @@ extern Datum bt_page_stats(PG_FUNCTION_ARGS);
 #define IS_BTREE(r) ((r)->rd_rel->relam == BTREE_AM_OID)
 
 #define CHECK_PAGE_OFFSET_RANGE(pg, offnum) { \
-		if ( !(FirstOffsetNumber<=(offnum) && \
-						(offnum)<=PageGetMaxOffsetNumber(pg)) ) \
+		if ( !(FirstOffsetNumber <= (offnum) && \
+						(offnum) <= PageGetMaxOffsetNumber(pg)) ) \
 			 elog(ERROR, "page offset number out of range"); }
 
+/* note: BlockNumber is unsigned, hence can't be negative */
 #define CHECK_RELATION_BLOCK_RANGE(rel, blkno) { \
-		if ( (blkno)<0 && RelationGetNumberOfBlocks((rel))<=(blkno) ) \
+		if ( RelationGetNumberOfBlocks(rel) <= (BlockNumber) (blkno) ) \
 			 elog(ERROR, "block number out of range"); }
 
 /* ------------------------------------------------
diff --git a/contrib/pgstattuple/pgstatindex.c b/contrib/pgstattuple/pgstatindex.c
index 6a64d3992a940fb4fbc4a726415df89e16d46d22..0c2c9a14484f55cd294d42ce298315b6fb7af3b1 100644
--- a/contrib/pgstattuple/pgstatindex.c
+++ b/contrib/pgstattuple/pgstatindex.c
@@ -48,12 +48,13 @@ extern Datum pg_relpages(PG_FUNCTION_ARGS);
 #define IS_BTREE(r) ((r)->rd_rel->relam == BTREE_AM_OID)
 
 #define CHECK_PAGE_OFFSET_RANGE(pg, offnum) { \
-		if ( !(FirstOffsetNumber<=(offnum) && \
-						(offnum)<=PageGetMaxOffsetNumber(pg)) ) \
+		if ( !(FirstOffsetNumber <= (offnum) && \
+						(offnum) <= PageGetMaxOffsetNumber(pg)) ) \
 			 elog(ERROR, "page offset number out of range"); }
 
+/* note: BlockNumber is unsigned, hence can't be negative */
 #define CHECK_RELATION_BLOCK_RANGE(rel, blkno) { \
-		if ( (blkno)<0 && RelationGetNumberOfBlocks((rel))<=(blkno) ) \
+		if ( RelationGetNumberOfBlocks(rel) <= (BlockNumber) (blkno) ) \
 			 elog(ERROR, "block number out of range"); }
 
 /* ------------------------------------------------