diff --git a/buildkite/clone_repositories.sh b/buildkite/clone_repositories.sh
index 86cbf371..c91f7df0 100755
--- a/buildkite/clone_repositories.sh
+++ b/buildkite/clone_repositories.sh
@@ -47,5 +47,5 @@ done
 
 for dir in dmd druntime phobos ; do
     echo "--- Building $dir"
-    make -C $dir -f posix.mak AUTO_BOOTSTRAP=1 --jobs=4
+    make -C $dir -f posix.mak AUTO_BOOTSTRAP=1 --jobs=4 BUILD=debug
 done
diff --git a/vars/runPipeline.groovy b/vars/runPipeline.groovy
index 7805a6de..101483e3 100644
--- a/vars/runPipeline.groovy
+++ b/vars/runPipeline.groovy
@@ -397,7 +397,7 @@ def buildDlang() {
             // expects previous one to be already built and present in parent
             // folder
 
-            def action = { sh "make -f posix.mak AUTO_BOOTSTRAP=1 --jobs=4" }
+            def action = { sh "make -f posix.mak AUTO_BOOTSTRAP=1 --jobs=4 BUILD=debug" }
 
             dir('dmd',      action)
             dir('druntime', action)