diff --git a/src/log.zig b/src/log.zig
index 229baca472dfade5e4fbeed1b9434f2349e70b49..056529e536cfcb36f0a2de9e762d2ddd49eb2229 100644
--- a/src/log.zig
+++ b/src/log.zig
@@ -10,8 +10,8 @@ pub fn init_thread() !void {}
 
 pub fn deinit_thread() void {}
 
-pub inline fn trace_begin(ctx: tracer.Ctx) void {
-    log.debug("{s}:{d}:{d} ({s})", .{ ctx.src.file, ctx.src.line, ctx.src.column, ctx.src.fn_name });
+pub inline fn trace_begin(ctx: tracer.Ctx, comptime ifmt: []const u8, iargs: anytype) void {
+    log.debug("{s}:{d}:{d} ({s})" ++ ifmt, .{ ctx.src.file, ctx.src.line, ctx.src.column, ctx.src.fn_name } ++ iargs);
 }
 
 pub inline fn trace_end(ctx: tracer.Ctx) void {
diff --git a/src/main.zig b/src/main.zig
index 6c8e7c9b6795607975c2c193029f0ad9db36d213..b86d2f8aa6334af2d0bf009436199b78cf466add 100644
--- a/src/main.zig
+++ b/src/main.zig
@@ -24,6 +24,6 @@ pub fn main() !void {
 }
 
 fn handler() void {
-    const t = tracer.trace(@src());
+    const t = tracer.trace(@src(), "", .{});
     defer t.end();
 }
diff --git a/src/mod.zig b/src/mod.zig
index 6393c726b8196551d4e2c55ae87bf0453c61e652..f4674b0b6ec79a4e2e39617b15c58eb8b105d6cf 100644
--- a/src/mod.zig
+++ b/src/mod.zig
@@ -26,11 +26,11 @@ pub fn deinit_thread() void {
     impl.deinit_thread();
 }
 
-pub inline fn trace(src: std.builtin.SourceLocation) Ctx {
+pub inline fn trace(src: std.builtin.SourceLocation, comptime fmt: []const u8, args: anytype) Ctx {
     const ctx = Ctx{
         .src = src,
     };
-    if (started) impl.trace_begin(ctx);
+    if (started) impl.trace_begin(ctx, fmt, args);
     return ctx;
 }
 
diff --git a/src/none.zig b/src/none.zig
index 20cbe73be18a2d3ec1292495b3be49ee725750d4..29ef21951d60822d6bd22926aebe5f7b9f656c96 100644
--- a/src/none.zig
+++ b/src/none.zig
@@ -10,8 +10,10 @@ pub fn init_thread() !void {}
 
 pub fn deinit_thread() void {}
 
-pub inline fn trace_begin(ctx: tracer.Ctx) void {
+pub inline fn trace_begin(ctx: tracer.Ctx, comptime ifmt: []const u8, iargs: anytype) void {
     _ = ctx;
+    _ = ifmt;
+    _ = iargs;
 }
 
 pub inline fn trace_end(ctx: tracer.Ctx) void {
diff --git a/src/spall.zig b/src/spall.zig
index 3429ad5152b51124c76d8e95ce2db2fe72ca16b9..fe48e99b0888ac949667aa57038dac9a542043b0 100644
--- a/src/spall.zig
+++ b/src/spall.zig
@@ -37,8 +37,8 @@ pub fn deinit_thread() void {
     log.debug("{s}", .{path});
 }
 
-pub inline fn trace_begin(ctx: tracer.Ctx) void {
-    const fmt = "{s}:{d}:{d} ({s})";
+pub inline fn trace_begin(ctx: tracer.Ctx, comptime ifmt: []const u8, iargs: anytype) void {
+    const fmt = "{s}:{d}:{d} ({s})" ++ ifmt;
     const args = .{
         if (ctx.src.file[0] == '/') ctx.src.file[trim_count..] else ctx.src.file,
         ctx.src.line,
@@ -49,10 +49,10 @@ pub inline fn trace_begin(ctx: tracer.Ctx) void {
         .pid = @intCast(pid),
         .tid = @intCast(tid),
         .time = @floatFromInt(std.time.microTimestamp()),
-        .name_len = @intCast(std.fmt.count(fmt, args)),
+        .name_len = @intCast(std.fmt.count(fmt, args ++ iargs)),
         .args_len = 0,
     }) catch return;
-    buffered_writer.writer().print(fmt, args) catch return;
+    buffered_writer.writer().print(fmt, args ++ iargs) catch return;
 }
 
 pub inline fn trace_end(ctx: tracer.Ctx) void {