diff --git a/src/vtab/csvtab.rs b/src/vtab/csvtab.rs
index 2177aab..b92a133 100644
--- a/src/vtab/csvtab.rs
+++ b/src/vtab/csvtab.rs
@@ -215,10 +215,8 @@ impl VTab for CSVTab {
             } else {
                 let mut record = csv::ByteRecord::new();
                 if try!(reader.read_byte_record(&mut record)) {
-                    let mut count = 0;
-                    for _ in record.iter() {
-                        cols.push(format!("c{}", count));
-                        count += 1;
+                    for (i, _) in record.iter().enumerate() {
+                        cols.push(format!("c{}", i));
                     }
                 }
             }
@@ -249,7 +247,7 @@ impl VTab for CSVTab {
 
     // Only a forward full table scan is supported.
     fn best_index(&self, info: &mut IndexInfo) -> Result<()> {
-        info.set_estimated_cost(1000000.);
+        info.set_estimated_cost(1_000_000.);
         Ok(())
     }
 
diff --git a/src/vtab/series.rs b/src/vtab/series.rs
index 167be5d..8ab9b8e 100644
--- a/src/vtab/series.rs
+++ b/src/vtab/series.rs
@@ -131,11 +131,11 @@ impl VTab for SeriesTab {
         if idx_num.contains(QueryPlanFlags::BOTH) {
             // Both start= and stop= boundaries are available.
             info.set_estimated_cost(
-                (2 - if idx_num.contains(QueryPlanFlags::STEP) {
+                f64::from(2 - if idx_num.contains(QueryPlanFlags::STEP) {
                     1
                 } else {
                     0
-                }) as f64,
+                }),
             );
             info.set_estimated_rows(1000);
             if info.num_of_order_by() == 1 {
@@ -145,8 +145,8 @@ impl VTab for SeriesTab {
                 info.set_order_by_consumed(true);
             }
         } else {
-            info.set_estimated_cost(2147483647f64);
-            info.set_estimated_rows(2147483647);
+            info.set_estimated_cost(2_147_483_647f64);
+            info.set_estimated_rows(2_147_483_647);
         }
         info.set_idx_num(idx_num.bits());
         Ok(())
@@ -201,7 +201,7 @@ impl VTabCursor for SeriesTabCursor {
             self.max_value = try!(args.get(i));
             i += 1;
         } else {
-            self.max_value = 0xffffffff;
+            self.max_value = 0xffff_ffff;
         }
         if idx_num.contains(QueryPlanFlags::STEP) {
             self.step = try!(args.get(i));