diff --git a/ext/zig_rb/build.zig b/ext/zig_rb/build.zig
index a8b3ffe..561fe54 100644
--- a/ext/zig_rb/build.zig
+++ b/ext/zig_rb/build.zig
@@ -1,20 +1,20 @@
 const std = @import("std");
 
-pub fn build(b: *std.build.Builder) void {
+pub fn build(b: *std.Build) void {
     // Standard release options allow the person running `zig build` to select
     // between Debug, ReleaseSafe, ReleaseFast, and ReleaseSmall.
     const target = b.standardTargetOptions(.{});
     const optimize = b.standardOptimizeOption(.{});
 
-    const lib = b.addSharedLibrary(.{ .name = "zig_rb", .root_source_file = .{ .path = "src/main.zig" }, .version = .{ .major = 0, .minor = 0, .patch = 1 }, .optimize = optimize, .target = target });
+    const lib = b.addSharedLibrary(.{ .name = "zig_rb", .root_source_file = b.path("src/main.zig"), .version = .{ .major = 0, .minor = 0, .patch = 1 }, .optimize = optimize, .target = target });
 
     // Ruby stuff
-    var ruby_libdir = std.os.getenv("RUBY_LIBDIR") orelse "";
-    lib.addLibraryPath(.{ .path = ruby_libdir });
-    var ruby_hdrdir = std.os.getenv("RUBY_HDRDIR") orelse "";
-    lib.addIncludePath(.{ .path = ruby_hdrdir });
-    var ruby_archhdrdir = std.os.getenv("RUBY_ARCHHDRDIR") orelse "";
-    lib.addIncludePath(.{ .path = ruby_archhdrdir });
+    const ruby_libdir = std.posix.getenv("RUBY_LIBDIR") orelse "";
+    lib.addLibraryPath(std.Build.LazyPath{ .cwd_relative = ruby_libdir });
+    const ruby_hdrdir = std.posix.getenv("RUBY_HDRDIR") orelse "";
+    lib.addIncludePath(std.Build.LazyPath{ .cwd_relative = ruby_hdrdir });
+    const ruby_archhdrdir = std.posix.getenv("RUBY_ARCHHDRDIR") orelse "";
+    lib.addIncludePath(std.Build.LazyPath{ .cwd_relative = ruby_archhdrdir });
 
     lib.linkSystemLibrary("c");
     b.installArtifact(lib);
diff --git a/ext/zig_rb/src/main.zig b/ext/zig_rb/src/main.zig
index e33c6f0..2546e0c 100644
--- a/ext/zig_rb/src/main.zig
+++ b/ext/zig_rb/src/main.zig
@@ -29,17 +29,17 @@ fn rb_hundred_doors(...) callconv(.C) ruby.VALUE {
     defer @cVaEnd(&ap);
 
     // first argument is `self`, but we don't use it so we need to discard it
-    var self = @cVaArg(&ap, ruby.VALUE);
+    const self = @cVaArg(&ap, ruby.VALUE);
     _ = self;
 
     // back and forth conversion from Ruby types to internal types + delegation to
     // actual `hundred_doors` function
-    var passes = ruby.NUM2INT(@cVaArg(&ap, ruby.VALUE));
+    const passes = ruby.NUM2INT(@cVaArg(&ap, ruby.VALUE));
     return ruby.INT2NUM(hundred_doors(passes));
 }
 
 export fn Init_libzig_rb() void {
-    var zig_rb_class: ruby.VALUE = ruby.rb_define_class("ZigRb", ruby.rb_cObject);
+    const zig_rb_class: ruby.VALUE = ruby.rb_define_class("ZigRb", ruby.rb_cObject);
     _ = ruby.rb_define_method(zig_rb_class, "hundred_doors", rb_hundred_doors, 1);
 }