diff --git a/src/base/client.zig b/src/base/client.zig
index 41c8d3a..f47df3c 100644
--- a/src/base/client.zig
+++ b/src/base/client.zig
@@ -271,12 +271,12 @@ test "decodes a simple response" {
     var output = std.ArrayList(u8).init(testing.allocator);
     defer output.deinit();
 
-    var response = "HTTP/1.1 404 Not Found\r\nHost: localhost\r\nContent-Length: 4\r\n\r\ngood";
-    var expected = "GET / HTTP/1.1\r\nHeader1: value1\r\nHeader2: value2\r\nHeader3: value3\r\nHeader4: value4\r\n\r\npayload";
+    const response = "HTTP/1.1 404 Not Found\r\nHost: localhost\r\nContent-Length: 4\r\n\r\ngood";
+    const expected = "GET / HTTP/1.1\r\nHeader1: value1\r\nHeader2: value2\r\nHeader3: value3\r\nHeader4: value4\r\n\r\npayload";
 
     var fbs = io.fixedBufferStream(response);
-    var reader = fbs.reader();
-    var writer = output.writer();
+    const reader = fbs.reader();
+    const writer = output.writer();
     var client = create(&read_buffer, reader, writer);
 
     const headers = [_]hzzp.Header{
@@ -323,7 +323,7 @@ test "decodes a simple response" {
 
     var payload_reader = client.reader();
 
-    var slice = try payload_reader.readAllAlloc(testing.allocator, 16);
+    const slice = try payload_reader.readAllAlloc(testing.allocator, 16);
     defer testing.allocator.free(slice);
 
     try testing.expectEqualStrings(slice, "good");
diff --git a/src/parser/request.zig b/src/parser/request.zig
index e0abadb..196c664 100644
--- a/src/parser/request.zig
+++ b/src/parser/request.zig
@@ -259,10 +259,10 @@ fn testNextField(parser: anytype, expected: ?Event) !void {
 
 test "decodes a simple request" {
     var read_buffer: [32]u8 = undefined;
-    var request = "GET / HTTP/1.1\r\nHost: localhost\r\nContent-Length: 4\r\n\r\ngood";
+    const request = "GET / HTTP/1.1\r\nHost: localhost\r\nContent-Length: 4\r\n\r\ngood";
 
     var fbs = io.fixedBufferStream(request);
-    var reader = fbs.reader();
+    const reader = fbs.reader();
     var parser = create(&read_buffer, reader);
 
     try testNextField(&parser, .{
@@ -306,10 +306,10 @@ test "decodes a simple request" {
 
 test "decodes a simple chunked request" {
     var read_buffer: [32]u8 = undefined;
-    var request = "GET / HTTP/1.1\r\nHost: localhost\r\nTransfer-Encoding: chunked\r\n\r\n4\r\ngood\r\n0\r\n";
+    const request = "GET / HTTP/1.1\r\nHost: localhost\r\nTransfer-Encoding: chunked\r\n\r\n4\r\ngood\r\n0\r\n";
 
     var fbs = io.fixedBufferStream(request);
-    var reader = fbs.reader();
+    const reader = fbs.reader();
     var parser = create(&read_buffer, reader);
 
     try testNextField(&parser, .{
@@ -353,10 +353,10 @@ test "decodes a simple chunked request" {
 
 test "decodes a simple chunked request with trailer" {
     var read_buffer: [32]u8 = undefined;
-    var request = "GET / HTTP/1.1\r\nHost: localhost\r\nTrailer: Expires\r\nTransfer-Encoding: chunked\r\n\r\n4\r\ngood\r\n0\r\nExpires: now\r\n\r\n";
+    const request = "GET / HTTP/1.1\r\nHost: localhost\r\nTrailer: Expires\r\nTransfer-Encoding: chunked\r\n\r\n4\r\ngood\r\n0\r\nExpires: now\r\n\r\n";
 
     var fbs = io.fixedBufferStream(request);
-    var reader = fbs.reader();
+    const reader = fbs.reader();
     var parser = create(&read_buffer, reader);
 
     try testNextField(&parser, .{
diff --git a/src/parser/response.zig b/src/parser/response.zig
index 2d7ff4e..08f1924 100644
--- a/src/parser/response.zig
+++ b/src/parser/response.zig
@@ -258,10 +258,10 @@ fn testNextField(parser: anytype, expected: ?Event) !void {
 
 test "decodes a simple response" {
     var read_buffer: [32]u8 = undefined;
-    var response = "HTTP/1.1 404 Not Found\r\nHost: localhost\r\nContent-Length: 4\r\n\r\ngood";
+    const response = "HTTP/1.1 404 Not Found\r\nHost: localhost\r\nContent-Length: 4\r\n\r\ngood";
 
     var fbs = io.fixedBufferStream(response);
-    var reader = fbs.reader();
+    const reader = fbs.reader();
     var parser = create(&read_buffer, reader);
 
     try testNextField(&parser, .{
@@ -305,10 +305,10 @@ test "decodes a simple response" {
 
 test "decodes a simple chunked response" {
     var read_buffer: [32]u8 = undefined;
-    var response = "HTTP/1.1 200 Ok\r\nHost: localhost\r\nTransfer-Encoding: chunked\r\n\r\n4\r\ngood\r\n0\r\n";
+    const response = "HTTP/1.1 200 Ok\r\nHost: localhost\r\nTransfer-Encoding: chunked\r\n\r\n4\r\ngood\r\n0\r\n";
 
     var fbs = io.fixedBufferStream(response);
-    var reader = fbs.reader();
+    const reader = fbs.reader();
     var parser = create(&read_buffer, reader);
 
     try testNextField(&parser, .{
@@ -352,10 +352,10 @@ test "decodes a simple chunked response" {
 
 test "decodes a simple chunked response with trailer" {
     var read_buffer: [32]u8 = undefined;
-    var response = "HTTP/1.1 200 Ok\r\nHost: localhost\r\nTrailer: Expires\r\nTransfer-Encoding: chunked\r\n\r\n4\r\ngood\r\n0\r\nExpires: now\r\n\r\n";
+    const response = "HTTP/1.1 200 Ok\r\nHost: localhost\r\nTrailer: Expires\r\nTransfer-Encoding: chunked\r\n\r\n4\r\ngood\r\n0\r\nExpires: now\r\n\r\n";
 
     var fbs = io.fixedBufferStream(response);
-    var reader = fbs.reader();
+    const reader = fbs.reader();
     var parser = create(&read_buffer, reader);
 
     try testNextField(&parser, .{