diff --git a/.gitignore b/.gitignore
index e8ae0a23..32e6b473 100644
--- a/.gitignore
+++ b/.gitignore
@@ -5,3 +5,7 @@ rgbgfx
 *.o
 *.exe
 .checkpatch-camelcase.*
+
+test/pokecrystal/*
+test/pokered/*
+test/ucity/*
diff --git a/test/run-tests.sh b/test/run-tests.sh
index e4b9b6a6..b93e0893 100755
--- a/test/run-tests.sh
+++ b/test/run-tests.sh
@@ -15,20 +15,30 @@ pushd link
 popd
 
 # Test some significant external projects that use RGBDS
+# When adding new ones, don't forget to add them to the .gitignore!
 
-git clone https://github.com/pret/pokecrystal.git --depth=1
+if [ ! -d pokecrystal ]; then
+	git clone https://github.com/pret/pokecrystal.git --depth=1
+fi
 pushd pokecrystal
+git pull
 make -j
 make compare
 popd
 
-git clone --recursive https://github.com/pret/pokered.git --depth=1
+if [ ! -d pokered ]; then
+	git clone --recursive https://github.com/pret/pokered.git --depth=1
+fi
 pushd pokered
+git pull
 make -j
 make compare
 popd
 
-git clone https://github.com/AntonioND/ucity.git --depth=1
+if [ ! -d ucity ]; then
+	git clone https://github.com/AntonioND/ucity.git --depth=1
+fi
 pushd ucity
+git pull
 make -j
 popd