diff --git a/ecs/build.zig b/ecs/build.zig
index 94ee020f..f686c53a 100644
--- a/ecs/build.zig
+++ b/ecs/build.zig
@@ -8,7 +8,7 @@ pub fn build(b: *std.build.Builder) void {
 }
 
 pub fn testStep(b: *std.build.Builder, mode: std.builtin.Mode, target: std.zig.CrossTarget) *std.build.RunStep {
-    const main_tests = b.addTestExe("ecs-tests", thisDir() ++ "/src/main.zig");
+    const main_tests = b.addTestExe("ecs-tests", (comptime thisDir()) ++ "/src/main.zig");
     main_tests.setBuildMode(mode);
     main_tests.setTarget(target);
     main_tests.install();