diff --git a/build.zig b/build.zig
index fbef277..34e5c05 100644
--- a/build.zig
+++ b/build.zig
@@ -35,6 +35,7 @@ pub fn build(b: *std.Build) void {
         .target = target,
         .optimize = optimize,
     });
+    exe.linkLibC();
 
     // This declares intent for the executable to be installed into the
     // standard location when the user invokes the "install" step (the default
diff --git a/src/config.zig b/src/config.zig
index 4e3c89c..a793da2 100644
--- a/src/config.zig
+++ b/src/config.zig
@@ -107,7 +107,7 @@ pub fn init(alloc: Allocator) !void {
 }
 
 pub fn config_file_path() []const u8 {
-    const home_path = std.os.getenv("HOME").?;
+    const home_path = std.posix.getenv("HOME").?;
     const home_dir = std.fs.openDirAbsolute(home_path, .{}) catch unreachable;
     const config_path = std.fs.path.join(allocator, &.{ home_path, ".config", "zootdeck" }) catch unreachable;
     home_dir.makePath(config_path) catch unreachable;
@@ -121,7 +121,7 @@ pub fn readfile(filename: []const u8) !Settings {
     cwd.access(filename, .{}) catch |err| switch (err) {
         error.FileNotFound => {
             warn("Warning: creating new {s}\n", .{filename});
-            try cwd.writeFile(filename, "{}\n");
+            try cwd.writeFile(.{ .sub_path = filename, .data = "{}\n" });
         },
         else => return err,
     };
diff --git a/src/db/file.zig b/src/db/file.zig
index 70c544d..7daa851 100644
--- a/src/db/file.zig
+++ b/src/db/file.zig
@@ -6,7 +6,7 @@ const Allocator = std.mem.Allocator;
 const cache_dir = "./cache";
 
 pub fn init() !void {
-    std.os.mkdir(cache_dir, 0o644) catch |err| {
+    std.posix.mkdir(cache_dir, 0o644) catch |err| {
         if (err != error.PathAlreadyExists) return err;
     };
 }
diff --git a/src/db/lmdb.zig b/src/db/lmdb.zig
index f2dc284..fead32d 100644
--- a/src/db/lmdb.zig
+++ b/src/db/lmdb.zig
@@ -23,7 +23,7 @@ pub fn init(allocator: Allocator) !void {
         warn("mdb_env_set_mapsize failed {}\n", .{mdb_ret});
         return error.BadValue;
     }
-    std.os.mkdir(dbpath, 0o0755) catch {};
+    std.posix.mkdir(dbpath, 0o0755) catch {};
     mdb_ret = c.mdb_env_open(env, util.sliceToCstr(allocator, dbpath), 0, 0o644);
     if (mdb_ret != 0) {
         warn("mdb_env_open failed {}\n", .{mdb_ret});
diff --git a/src/util.zig b/src/util.zig
index ba9fd6c..204bcbc 100644
--- a/src/util.zig
+++ b/src/util.zig
@@ -14,7 +14,7 @@ pub fn sliceAddNull(allocator: Allocator, str: []const u8) []const u8 {
 
 pub fn sliceToCstr(allocator: Allocator, str: []const u8) [*]u8 {
     var str_null: []u8 = allocator.alloc(u8, str.len + 1) catch unreachable;
-    std.mem.copy(u8, str_null[0..], str);
+    std.mem.copyForwards(u8, str_null[0..], str);
     str_null[str.len] = 0;
     return str_null.ptr;
 }
@@ -30,8 +30,8 @@ pub fn log(comptime msg: []const u8, args: anytype) void {
     const tid = thread.self();
     const tid_name = thread.name(tid);
     //const tz = std.os.timezone.tz_minuteswest;
-    var tz = std.os.timezone{ .tz_minuteswest = 0, .tz_dsttime = 0 };
-    std.os.gettimeofday(null, &tz); // does not set tz
+    var tz = std.posix.timezone{ .tz_minuteswest = 0, .tz_dsttime = 0 };
+    std.posix.gettimeofday(null, &tz); // does not set tz
     const time_str = "Z"; //std.fmt.allocPrint(alloc, "{d}-{d:0>2}-{d:0>2} {d:0>2}:{d:0>2}:{d:0>2}", .{ yday.year, mday.month.numeric(), mday.day_index + 1, dsec.getHoursIntoDay(), dsec.getMinutesIntoHour(), dsec.getSecondsIntoMinute() }) catch unreachable;
     _ = time_str;
     _ = tid_name;