diff --git a/.gitignore b/.gitignore
index f7595dd..54b7224 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,5 +1,7 @@
 *.csv
 main
 main.o
+.zig-cache
 zig-cache
 zig-out
+result
diff --git a/build.zig b/build.zig
index a5f282f..9a26412 100644
--- a/build.zig
+++ b/build.zig
@@ -29,11 +29,16 @@ pub fn build(b: *std.Build) void {
     const optimize = b.standardOptimizeOption(.{});
 
     // Module declarations
-    const strings = b.addModule("sonic-strings", .{ .root_source_file = .{ .path = "src/strings.zig" } });
-    const sonic = b.addModule("sonic", .{ .root_source_file = .{ .path = "src/records.zig" } });
+    const strings = b.addModule("sonic-strings", .{ .root_source_file = b.path("src/strings.zig") });
+    const sonic = b.addModule(
+        "sonic",
+        .{ .root_source_file = b.path("src/records.zig") },
+    );
     sonic.addImport("strings", strings);
 
-    const fastaModule = b.addModule("sonic-fasta", .{ .root_source_file = .{ .path = "src/fasta-lib.zig" } });
+    const fastaModule = b.addModule("sonic-fasta", .{
+        .root_source_file = b.path("src/fasta-lib.zig"),
+    });
     fastaModule.addImport("strings", strings);
     fastaModule.addImport("sonic", sonic);
 
@@ -41,11 +46,9 @@ pub fn build(b: *std.Build) void {
         .name = "pdb2fasta",
         // In this case the main source file is merely a path, however, in more
         // complicated build scripts, this could be a generated file.
-        .root_source_file = .{ .path = "src/fasta.zig" },
+        .root_source_file = b.path("src/fasta.zig"),
         .target = target,
         .optimize = optimize,
-        .use_lld = false,
-        .use_llvm = false,
     });
     fasta.root_module.addImport("sonic-fasta", fastaModule);
     fasta.root_module.addImport("sonic", sonic);
@@ -61,11 +64,9 @@ pub fn build(b: *std.Build) void {
         .name = "sonic-pdb-parser",
         // In this case the main source file is merely a path, however, in more
         // complicated build scripts, this could be a generated file.
-        .root_source_file = .{ .path = "src/main.zig" },
+        .root_source_file = b.path("src/main.zig"),
         .target = target,
         .optimize = optimize,
-        .use_lld = false,
-        .use_llvm = false,
     });
     exe.root_module.addImport("sonic", sonic);
     exe.root_module.addImport("strings", strings);
@@ -101,11 +102,9 @@ pub fn build(b: *std.Build) void {
     // Creates a step for unit testing. This only builds the test executable
     // but does not run it.
     const unit_tests = b.addTest(.{
-        .root_source_file = .{ .path = "src/main.zig" },
+        .root_source_file = b.path("src/main.zig"),
         .target = target,
         .optimize = optimize,
-        .use_llvm = false,
-        .use_lld = false,
     });
     unit_tests.root_module.addImport("sonic", sonic);
     unit_tests.root_module.addImport("strings", strings);
@@ -114,8 +113,6 @@ pub fn build(b: *std.Build) void {
         .root_source_file = b.path("src/records.zig"),
         .target = target,
         .optimize = optimize,
-        .use_llvm = false,
-        .use_lld = false,
     });
     sonic_test.root_module.addImport("strings", strings);
 
@@ -123,8 +120,6 @@ pub fn build(b: *std.Build) void {
         .root_source_file = b.path("src/strings.zig"),
         .target = target,
         .optimize = optimize,
-        .use_llvm = false,
-        .use_lld = false,
     });
 
     const run_unit_tests = b.addRunArtifact(unit_tests);
diff --git a/flake.lock b/flake.lock
index 6d42d82..aa618a6 100644
--- a/flake.lock
+++ b/flake.lock
@@ -3,11 +3,11 @@
     "flake-compat": {
       "flake": false,
       "locked": {
-        "lastModified": 1673956053,
-        "narHash": "sha256-4gtG9iQuiKITOjNQQeQIpoIB6b16fm+504Ch3sNKLd8=",
+        "lastModified": 1696426674,
+        "narHash": "sha256-kvjfFW7WAETZlt09AgDn1MrtKzP7t90Vf7vypd3OL1U=",
         "owner": "edolstra",
         "repo": "flake-compat",
-        "rev": "35bb57c0c8d8b62bbfd284272c928ceb64ddbde9",
+        "rev": "0f9255e01c2351cc7d116c072cb317785dd33b33",
         "type": "github"
       },
       "original": {
@@ -35,12 +35,15 @@
       }
     },
     "flake-utils_2": {
+      "inputs": {
+        "systems": "systems_2"
+      },
       "locked": {
-        "lastModified": 1659877975,
-        "narHash": "sha256-zllb8aq3YO3h8B/U0/J1WBgAL8EX5yWf5pMj3G0NAmc=",
+        "lastModified": 1705309234,
+        "narHash": "sha256-uNRRNRKmJyCRC/8y1RqBkqWBLM034y4qN7EprSdmgyA=",
         "owner": "numtide",
         "repo": "flake-utils",
-        "rev": "c0e246b9b83f637f4681389ecabcb2681b4f3af0",
+        "rev": "1ef2e671c3b0c19053962c07dbda38332dcebf26",
         "type": "github"
       },
       "original": {
@@ -71,11 +74,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1713596654,
-        "narHash": "sha256-LJbHQQ5aX1LVth2ST+Kkse/DRzgxlVhTL1rxthvyhZc=",
+        "lastModified": 1723221148,
+        "narHash": "sha256-7pjpeQlZUNQ4eeVntytU3jkw9dFK3k1Htgk2iuXjaD8=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "fd16bb6d3bcca96039b11aa52038fafeb6e4f4be",
+        "rev": "154bcb95ad51bc257c2ce4043a725de6ca700ef6",
         "type": "github"
       },
       "original": {
@@ -108,6 +111,21 @@
         "type": "github"
       }
     },
+    "systems_2": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
+    },
     "zig-overlay": {
       "inputs": {
         "flake-compat": "flake-compat",
@@ -117,11 +135,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1713572548,
-        "narHash": "sha256-bYNsY9HwrV8+eJGRYvfLEP6/Sgf2Kr9qNbnB91OYMMM=",
+        "lastModified": 1723291738,
+        "narHash": "sha256-C3DobEyzw47Rvs9tRpe8XGrqGl4hLABu1wocjxczJ/U=",
         "owner": "mitchellh",
         "repo": "zig-overlay",
-        "rev": "76bccd85db6a182dfcbf8a5f4b540953f029a12c",
+        "rev": "d132903f2088ee03cf3561368a81cd3bd850f5ff",
         "type": "github"
       },
       "original": {
diff --git a/flake.nix b/flake.nix
index bece495..faf5048 100644
--- a/flake.nix
+++ b/flake.nix
@@ -21,7 +21,7 @@
     flake-utils.lib.eachSystem systems (system:
       let
         pkgs = nixpkgs.legacyPackages.${system};
-        zig = zig-overlay.packages.${system}.master;
+        zig = zig-overlay.packages.${system}."0.13.0";
       in
       rec {
         formatter = nixpkgs.legacyPackages.${system}.nixpkgs-fmt;
diff --git a/src/fasta-lib.zig b/src/fasta-lib.zig
index 7b3ba59..ff47ad1 100644
--- a/src/fasta-lib.zig
+++ b/src/fasta-lib.zig
@@ -3,7 +3,7 @@ const strings = @import("strings");
 const records = @import("sonic");
 const Record = records.Record;
 
-const newTerms = std.ComptimeStringMap(u8, .{
+const newTerms = std.StaticStringMap(u8).initComptime(.{
     .{ "ALA", 'A' },
     .{ "VAL", 'V' },
     .{ "PHE", 'F' },