diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 17920559..16ea61aa 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -152,5 +152,5 @@ If one *does* exist, RGBGFX's return status is ignored, but its output **must**
 3. Add the project to `test/run-tests.sh`: add a new `test_downstream` line at the bottom, following the existing pattern:
 
    ```sh
-   test_downstream  <owner>  <repo>  <makefile target>
+   test_downstream  <owner>  <repo>  <makefile target>  <build file>  <sha1 hash of build file>
    ```
diff --git a/test/patches/libbet.patch b/test/patches/libbet.patch
index 654d3193..36671a5d 100644
--- a/test/patches/libbet.patch
+++ b/test/patches/libbet.patch
@@ -1,5 +1,5 @@
 diff --git a/makefile b/makefile
-index 6513518..35826eb 100644
+index 6513518..ba14638 100644
 --- a/makefile
 +++ b/makefile
 @@ -85,10 +85,10 @@ $(title).gb: $(objlisto)
@@ -15,3 +15,12 @@ index 6513518..35826eb 100644
  
  # Files that will be included with incbin
  
+@@ -108,7 +108,7 @@ obj/gb/sgb.o: \
+ 
+ # Local variable allocation
+ 
+-obj/gb/localvars.z80: tools/savescan.py $(wildcard src/*.z80)
++obj/gb/localvars.z80: tools/savescan.py $(sort $(wildcard src/*.z80))
+ 	$(PY) $^ -o $@
+ 
+ # Graphics conversion
diff --git a/test/patches/ucity.patch b/test/patches/ucity.patch
index 0740e247..be49c6df 100644
--- a/test/patches/ucity.patch
+++ b/test/patches/ucity.patch
@@ -1,8 +1,17 @@
 diff --git a/Makefile b/Makefile
-index 22c65e9..e7c888d 100644
+index 22c65e9..fce4930 100644
 --- a/Makefile
 +++ b/Makefile
-@@ -51,7 +51,7 @@ ASMFILES := $(foreach dir,$(SOURCE_ALL_DIRS),$(wildcard $(dir)/*.asm))
+@@ -44,14 +44,14 @@ BIN := $(NAME).$(EXT)
+ COMPAT_BIN := $(NAME)_compat.$(EXT)
+ 
+ # List of relative paths to all folders and subfolders with code or data.
+-SOURCE_ALL_DIRS := $(shell find $(SOURCE) -type d -print)
++SOURCE_ALL_DIRS := $(sort $(shell find $(SOURCE) -type d -print))
+ 
+ # All files with extension asm are assembled.
+-ASMFILES := $(foreach dir,$(SOURCE_ALL_DIRS),$(wildcard $(dir)/*.asm))
++ASMFILES := $(foreach dir,$(SOURCE_ALL_DIRS),$(sort $(wildcard $(dir)/*.asm)))
  
  # List of include directories: All source and data folders.
  # A '/' is appended to the path.
diff --git a/test/run-tests.sh b/test/run-tests.sh
index 1097c167..8689c7ab 100755
--- a/test/run-tests.sh
+++ b/test/run-tests.sh
@@ -54,21 +54,26 @@ done
 # When updating subprojects, change the commit being checked out, and set the `shallow-since`
 # to the day before, to reduce the amount of refs being transferred and thus speed up CI.
 
-test_downstream() { # owner repo make-target
+test_downstream() { # owner repo make-target build-file build-hash
 	if ! pushd "$2"; then
 		echo >&2 'Please run `'"$FETCH_TEST_DEPS"'` before running the test suite'
 		return 1
 	fi
 	make clean
 	make -j4 "$3" RGBDS=../../
+	hash="$(sha1sum -b "$4" | head -c 40)"
+	if [ "$hash" != "$5" ]; then
+		echo >&2 'SHA-1 hash of '"$4"' did not match: '"$hash"
+		return 1
+	fi
 	popd
 }
 
 if "$nonfree"; then
-	test_downstream pret  pokecrystal      compare
-	test_downstream pret  pokered          compare
-	test_downstream zladx LADX-Disassembly default
+	test_downstream pret  pokecrystal      compare pokecrystal.gbc f4cd194bdee0d04ca4eac29e09b8e4e9d818c133
+	test_downstream pret  pokered          compare pokered.gbc     ea9bcae617fdf159b045185467ae58b2e4a48b9a
+	test_downstream zladx LADX-Disassembly default azle.gbc        d90ac17e9bf17b6c61624ad9f05447bdb5efc01a
 fi
-test_downstream AntonioND ucity   all
-test_downstream pinobatch libbet  all
-test_downstream LIJI32    SameBoy bootroms
+test_downstream AntonioND ucity   all      ucity.gbc 67e67a4eaefb12ddc98d3caa8959102b885c0405
+test_downstream pinobatch libbet  all      libbet.gb 8bf954a61cd31fa665ad0abb7cea14561919a12c
+test_downstream LIJI32    SameBoy bootroms build/bin/BootROMs/cgb_boot.bin 113903775a9d34b798c2f8076672da6626815a91