diff --git a/build.zig b/build.zig
index 18e8286..db4b25e 100755
--- a/build.zig
+++ b/build.zig
@@ -1,17 +1,18 @@
 const std = @import("std");
 
-pub fn build(b: *std.build.Builder) void {
+pub fn build(b: *std.Build) void {
+    const target = b.standardTargetOptions(.{});
+
     // Standard release options allow the person running `zig build` to select
     // between Debug, ReleaseSafe, ReleaseFast, and ReleaseSmall.
-    const mode = b.standardReleaseOptions();
-
-    const lib = b.addStaticLibrary("ctregex", "ctregex.zig");
-    lib.setBuildMode(mode);
-    lib.install();
+    const optimize = b.standardOptimizeOption(.{});
 
-    const main_tests = b.addTest("tests.zig");
-    main_tests.setBuildMode(mode);
+    const lib = b.addStaticLibrary(.{
+        .name = "ctregex",
+        .root_source_file = .{ .path = "ctregex.zig" },
+        .target = target,
+        .optimize = optimize,
+    });
 
-    const test_step = b.step("test", "Run library tests");
-    test_step.dependOn(&main_tests.step);
+    b.installArtifact(lib);
 }
diff --git a/ctregex.zig b/ctregex.zig
index bc14fd1..35c9f05 100644
--- a/ctregex.zig
+++ b/ctregex.zig
@@ -630,7 +630,7 @@ const RegexParser = struct {
         fn ctStr(comptime self: Brackets) []const u8 {
             var str: []const u8 = "[";
             if (self.is_exclusive) str = str ++ "<not> ";
-            for (self.rules) |rule, idx| {
+            for (self.rules, 0..) |rule, idx| {
                 if (idx > 0) str = str ++ " ";
                 str = str ++ switch (rule) {
                     .char => |c| ctUtf8EncodeChar(c),
@@ -885,7 +885,7 @@ pub fn MatchResult(comptime regex: []const u8, comptime options: MatchOptions) t
     if (RegexParser.parse(regex)) |parsed| {
         const capture_len = parsed.captures.len;
         var capture_names: [capture_len]?[]const u8 = undefined;
-        for (parsed.captures) |capt, idx| {
+        for (parsed.captures, 0..) |capt, idx| {
             if (capt.capture_info) |info| {
                 capture_names[idx] = info.name;
             }
@@ -906,7 +906,7 @@ pub fn MatchResult(comptime regex: []const u8, comptime options: MatchOptions) t
             pub usingnamespace if (capture_len != 0)
                 struct {
                     pub fn capture(self: Self, comptime name: []const u8) ?[]const CharT {
-                        inline for (capture_names2) |maybe_name, curr_idx| {
+                        inline for (capture_names2, 0..) |maybe_name, curr_idx| {
                             if (maybe_name) |curr_name| {
                                 if (comptime std.mem.eql(u8, name, curr_name))
                                     return self.captures[curr_idx];