diff --git a/makefile b/makefile
index 147506a..fd36b15 100644
--- a/makefile
+++ b/makefile
@@ -1,16 +1,16 @@
 DENO := deno
 
 tests: clean fmt-check
-	$(DENO) test --coverage=cov_profile *.test.mjs
+	$(DENO) test --coverage=cov_profile *.test.ts
 
 tests-cov: tests
 	$(DENO) coverage cov_profile --lcov > cov_profile/cov.lcov
 
 fmt:
-	$(DENO) fmt *.mjs
+	$(DENO) fmt *.ts
 
 fmt-check:
-	$(DENO) fmt *.mjs --check
+	$(DENO) fmt *.ts --check
 
 clean:
 	rm -rf cov_profile