diff --git a/test/patches/gb-starter-kit.patch b/test/patches/gb-starter-kit.patch
new file mode 100644
index 0000000000..ef69ac3d4d
--- /dev/null
+++ b/test/patches/gb-starter-kit.patch
@@ -0,0 +1,31 @@
+diff --git a/Makefile b/Makefile
+index fc5b476..a76dbec 100644
+--- a/Makefile
++++ b/Makefile
+@@ -18,6 +18,26 @@ ifeq ($(strip $(shell which rm)),)
+ 	filesize = powershell Write-Output $$('def NB_PB$2_BLOCKS equ ' + [string] [int] (([IO.File]::ReadAllBytes('$1').Length + $2 - 1) / $2))
+ endif
+ 
++$(info ${OS})
++$(info ${MAKE_HOST})
++$(info ${MAKE_VERSION})
++ifeq (${OS},Windows_NT)
++ifneq ($(filter -j%,${MAKEFLAGS}),)
++$(warning Parallel builds are broken on Windows.)
++$(warning Please see https://github.com/ISSOtm/gb-starter-kit/issues/1#issuecomment-1793775226 for details.)
++.NOTPARALLEL: # Delete this line if you want to have parallel builds regardless!
++endif
++# Make doesn't have a good way to compare versions, so I'm just going to assume that nobody installs
++# a version from 2006 on their own ;)
++else ifeq (${MAKE_VERSION},3.81)
++ifneq ($(filter -j%,${MAKEFLAGS}),)
++$(warning Parallel builds are broken with macOS' bundled version of Make.)
++$(warning Please consider installing Make from Homebrew (`brew install make`, **make sure to read the caveats**).)
++$(warning Please see https://github.com/ISSOtm/gb-starter-kit/issues/1#issuecomment-1793775226 for details.)
++.NOTPARALLEL: # Delete this line if you want to have parallel builds regardless!
++endif
++endif
++
+ RGBDS   ?= # Shortcut if you want to use a local copy of RGBDS.
+ RGBASM  := ${RGBDS}rgbasm
+ RGBLINK := ${RGBDS}rgblink
diff --git a/test/run-tests.sh b/test/run-tests.sh
index 716ec8ab10..d1cf643d2e 100755
--- a/test/run-tests.sh
+++ b/test/run-tests.sh
@@ -60,6 +60,7 @@ test_downstream() { # owner/repo make-target
 		return 1
 	fi
 	make clean
+	cat Makefile
 	make -j4 $2 RGBDS=../../
 	popd
 }