diff --git a/flow/connectors/postgres/sink.go b/flow/connectors/postgres/sink.go
index e1aa183b7a..0da2387dc7 100644
--- a/flow/connectors/postgres/sink.go
+++ b/flow/connectors/postgres/sink.go
@@ -45,7 +45,7 @@ type PgCopyReader struct {
 
 func NewPgCopyPipe() (PgCopyReader, PgCopyWriter) {
 	read, write := io.Pipe()
-	schema := PgCopyShared{schemaLatch: make(chan struct{}, 0)}
+	schema := PgCopyShared{schemaLatch: make(chan struct{})}
 	return PgCopyReader{PipeReader: read, schema: &schema},
 		PgCopyWriter{PipeWriter: write, schema: &schema}
 }
@@ -174,7 +174,7 @@ func (p PgCopyWriter) ExecuteQueryWithTx(
 	// TODO use pgx simple query arg parsing code (it's internal, need to copy)
 	// TODO correctly interpolate
 	for i, arg := range args {
-		query = strings.ReplaceAll(query, fmt.Sprintf("$%d", i), fmt.Sprint(arg))
+		query = strings.ReplaceAll(query, fmt.Sprintf("$%d", i+1), fmt.Sprint(arg))
 	}
 
 	copyQuery := fmt.Sprintf("COPY %s (%s) TO STDOUT", query, strings.Join(cols, ","))