diff --git a/src/bootstrap/builder.rs b/src/bootstrap/builder.rs
index f2f0906ff4e..a7add4cd559 100644
--- a/src/bootstrap/builder.rs
+++ b/src/bootstrap/builder.rs
@@ -540,6 +540,7 @@ impl<'a> Builder<'a> {
                 Kind::Check | Kind::Clippy | Kind::Fix | Kind::Run | Kind::Format => 0,
             }
         };
+
         Builder {
             build,
             top_stage,
@@ -566,7 +567,20 @@ impl<'a> Builder<'a> {
             Subcommand::Format { .. } | Subcommand::Clean { .. } => panic!(),
         };
 
-        Self::new_internal(build, kind, paths.to_owned())
+        let this = Self::new_internal(build, kind, paths.to_owned());
+
+        // CI should always run stage 2 builds, unless it specifically states otherwise
+        #[cfg(not(test))]
+        if build.config.stage.is_none() && build.ci_env != crate::CiEnv::None {
+            match kind {
+                Kind::Test | Kind::Doc | Kind::Build | Kind::Bench | Kind::Dist | Kind::Install => {
+                    assert_eq!(this.top_stage, 2)
+                }
+                _ => {}
+            }
+        }
+
+        this
     }
 
     pub fn execute_cli(&self) {
diff --git a/src/bootstrap/mk/Makefile.in b/src/bootstrap/mk/Makefile.in
index e5b9f27c258..1564cfb0619 100644
--- a/src/bootstrap/mk/Makefile.in
+++ b/src/bootstrap/mk/Makefile.in
@@ -9,8 +9,8 @@ endif
 BOOTSTRAP := $(CFG_PYTHON) $(CFG_SRC_DIR)src/bootstrap/bootstrap.py
 
 all:
-	$(Q)$(BOOTSTRAP) build $(BOOTSTRAP_ARGS)
-	$(Q)$(BOOTSTRAP) doc $(BOOTSTRAP_ARGS)
+	$(Q)$(BOOTSTRAP) build --stage 2 $(BOOTSTRAP_ARGS)
+	$(Q)$(BOOTSTRAP) doc --stage 2 $(BOOTSTRAP_ARGS)
 
 help:
 	$(Q)echo 'Welcome to the rustbuild build system!'
@@ -31,17 +31,17 @@ rustc-stage2:
 
 docs: doc
 doc:
-	$(Q)$(BOOTSTRAP) doc $(BOOTSTRAP_ARGS)
+	$(Q)$(BOOTSTRAP) doc --stage 2 $(BOOTSTRAP_ARGS)
 nomicon:
-	$(Q)$(BOOTSTRAP) doc src/doc/nomicon $(BOOTSTRAP_ARGS)
+	$(Q)$(BOOTSTRAP) doc --stage 2 src/doc/nomicon $(BOOTSTRAP_ARGS)
 book:
-	$(Q)$(BOOTSTRAP) doc src/doc/book $(BOOTSTRAP_ARGS)
+	$(Q)$(BOOTSTRAP) doc --stage 2 src/doc/book $(BOOTSTRAP_ARGS)
 standalone-docs:
-	$(Q)$(BOOTSTRAP) doc src/doc $(BOOTSTRAP_ARGS)
+	$(Q)$(BOOTSTRAP) doc --stage 2 src/doc $(BOOTSTRAP_ARGS)
 check:
-	$(Q)$(BOOTSTRAP) test $(BOOTSTRAP_ARGS)
+	$(Q)$(BOOTSTRAP) test --stage 2 $(BOOTSTRAP_ARGS)
 check-aux:
-	$(Q)$(BOOTSTRAP) test \
+	$(Q)$(BOOTSTRAP) test --stage 2 \
 		src/tools/cargo \
 		src/tools/cargotest \
 		$(BOOTSTRAP_ARGS)
@@ -51,18 +51,18 @@ dist:
 	$(Q)$(BOOTSTRAP) dist $(BOOTSTRAP_ARGS)
 distcheck:
 	$(Q)$(BOOTSTRAP) dist $(BOOTSTRAP_ARGS)
-	$(Q)$(BOOTSTRAP) test distcheck $(BOOTSTRAP_ARGS)
+	$(Q)$(BOOTSTRAP) test --stage 2 distcheck $(BOOTSTRAP_ARGS)
 install:
 	$(Q)$(BOOTSTRAP) install $(BOOTSTRAP_ARGS)
 tidy:
-	$(Q)$(BOOTSTRAP) test src/tools/tidy $(BOOTSTRAP_ARGS)
+	$(Q)$(BOOTSTRAP) test --stage 2 src/tools/tidy $(BOOTSTRAP_ARGS)
 prepare:
-	$(Q)$(BOOTSTRAP) build nonexistent/path/to/trigger/cargo/metadata
+	$(Q)$(BOOTSTRAP) build --stage 2 nonexistent/path/to/trigger/cargo/metadata
 
 check-stage2-T-arm-linux-androideabi-H-x86_64-unknown-linux-gnu:
-	$(Q)$(BOOTSTRAP) test --target arm-linux-androideabi
+	$(Q)$(BOOTSTRAP) test --stage 2 --target arm-linux-androideabi
 check-stage2-T-x86_64-unknown-linux-musl-H-x86_64-unknown-linux-gnu:
-	$(Q)$(BOOTSTRAP) test --target x86_64-unknown-linux-musl
+	$(Q)$(BOOTSTRAP) test --stage 2 --target x86_64-unknown-linux-musl
 
 TESTS_IN_2 := \
 	src/test/ui \
@@ -70,18 +70,18 @@ TESTS_IN_2 := \
 	src/tools/linkchecker
 
 ci-subset-1:
-	$(Q)$(BOOTSTRAP) test $(TESTS_IN_2:%=--exclude %)
+	$(Q)$(BOOTSTRAP) test --stage 2 $(TESTS_IN_2:%=--exclude %)
 ci-subset-2:
-	$(Q)$(BOOTSTRAP) test $(TESTS_IN_2)
+	$(Q)$(BOOTSTRAP) test --stage 2 $(TESTS_IN_2)
 
 TESTS_IN_MINGW_2 := \
 	src/test/ui \
 	src/test/compile-fail
 
 ci-mingw-subset-1:
-	$(Q)$(BOOTSTRAP) test $(TESTS_IN_MINGW_2:%=--exclude %)
+	$(Q)$(BOOTSTRAP) test --stage 2 $(TESTS_IN_MINGW_2:%=--exclude %)
 ci-mingw-subset-2:
-	$(Q)$(BOOTSTRAP) test $(TESTS_IN_MINGW_2)
+	$(Q)$(BOOTSTRAP) test --stage 2 $(TESTS_IN_MINGW_2)
 
 
 .PHONY: dist