diff --git a/contrib/btree_gist/btree_cash.c b/contrib/btree_gist/btree_cash.c
index 6ac97e2b12..546b948ea4 100644
--- a/contrib/btree_gist/btree_cash.c
+++ b/contrib/btree_gist/btree_cash.c
@@ -106,7 +106,7 @@ cash_dist(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 				 errmsg("money out of range")));
 
-	ra = Abs(r);
+	ra = i64abs(r);
 
 	PG_RETURN_CASH(ra);
 }
diff --git a/contrib/btree_gist/btree_int8.c b/contrib/btree_gist/btree_int8.c
index df2b0d174b..7c63a5b6dc 100644
--- a/contrib/btree_gist/btree_int8.c
+++ b/contrib/btree_gist/btree_int8.c
@@ -106,7 +106,7 @@ int8_dist(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
 				 errmsg("bigint out of range")));
 
-	ra = Abs(r);
+	ra = i64abs(r);
 
 	PG_RETURN_INT64(ra);
 }
diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index a8b025f43f..4e9935e01d 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -4468,7 +4468,7 @@ AddVerboseIntPart(char *cp, int64 value, const char *units,
 	if (*is_zero)
 	{
 		*is_before = (value < 0);
-		value = Abs(value);
+		value = i64abs(value);
 	}
 	else if (*is_before)
 		value = -value;
@@ -4569,8 +4569,8 @@ EncodeInterval(struct pg_itm *itm, int style, char *str)
 
 					sprintf(cp, "%c%d-%d %c%lld %c%lld:%02d:",
 							year_sign, abs(year), abs(mon),
-							day_sign, (long long) Abs(mday),
-							sec_sign, (long long) Abs(hour), abs(min));
+							day_sign, (long long) i64abs(mday),
+							sec_sign, (long long) i64abs(hour), abs(min));
 					cp += strlen(cp);
 					cp = AppendSeconds(cp, sec, fsec, MAX_INTERVAL_PRECISION, true);
 					*cp = '\0';
@@ -4642,7 +4642,7 @@ EncodeInterval(struct pg_itm *itm, int style, char *str)
 				sprintf(cp, "%s%s%02lld:%02d:",
 						is_zero ? "" : " ",
 						(minus ? "-" : (is_before ? "+" : "")),
-						(long long) Abs(hour), abs(min));
+						(long long) i64abs(hour), abs(min));
 				cp += strlen(cp);
 				cp = AppendSeconds(cp, sec, fsec, MAX_INTERVAL_PRECISION, true);
 				*cp = '\0';
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 34efa121b4..0a9b93f263 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -564,7 +564,7 @@ pg_size_pretty(PG_FUNCTION_ARGS)
 		uint8		bits;
 
 		/* use this unit if there are no more units or we're below the limit */
-		if (unit[1].name == NULL || Abs(size) < unit->limit)
+		if (unit[1].name == NULL || i64abs(size) < unit->limit)
 		{
 			if (unit->round)
 				size = half_rounded(size);
diff --git a/src/include/c.h b/src/include/c.h
index c8f72e44d8..405d53cb56 100644
--- a/src/include/c.h
+++ b/src/include/c.h
@@ -1282,6 +1282,15 @@ extern int	fdatasync(int fildes);
 #define strtou64(str, endptr, base) ((uint64) strtoull(str, endptr, base))
 #endif
 
+/*
+ * Similarly, wrappers around labs()/llabs() matching our int64.
+ */
+#ifdef HAVE_LONG_INT_64
+#define i64abs(i) labs(i)
+#else
+#define i64abs(i) llabs(i)
+#endif
+
 /*
  * Use "extern PGDLLIMPORT ..." to declare variables that are defined
  * in the core backend and need to be accessible by loadable modules.