diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index c7ac5fa..aa1830b 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -53,4 +53,5 @@ jobs:
 
       - name: Integration test
         run: bundle exec rake check
+        if: ${{ ( matrix.ruby != 'debug' && matrix.os == 'linux-latest' ) || ( matrix.ruby != 'debug' && matrix.os == 'macos-latest' ) }}
         # continue-on-error: ${{ matrix.ignore-pkg-error || (matrix.ruby == 'debug') }}
diff --git a/ext/digest/depend b/ext/digest/depend
deleted file mode 100644
index 1d9b1fb..0000000
--- a/ext/digest/depend
+++ /dev/null
@@ -1,3 +0,0 @@
-do-install-rb: do-install-headers
-do-install-headers:
-	$(Q) $(RUBY) install_headers.rb $(srcdir)/digest.h $(DESTDIR)$(HDRDIR)