diff --git a/src/backend/utils/adt/numeric.c b/src/backend/utils/adt/numeric.c
index 898c52099b..a42a6ceb18 100644
--- a/src/backend/utils/adt/numeric.c
+++ b/src/backend/utils/adt/numeric.c
@@ -3694,7 +3694,10 @@ numeric_sqrt(PG_FUNCTION_ARGS)
 	init_var(&result);
 
 	/* Assume the input was normalized, so arg.weight is accurate */
-	sweight = (arg.weight + 1) * DEC_DIGITS / 2 - 1;
+	if (arg.weight < 0)
+		sweight = (arg.weight + 1) * DEC_DIGITS / 2 - 1;
+	else
+		sweight = arg.weight * DEC_DIGITS / 2 + 1;
 
 	rscale = NUMERIC_MIN_SIG_DIGITS - sweight;
 	rscale = Max(rscale, arg.dscale);