diff --git a/build.sh b/build.sh
index c0a624e..31ca658 100755
--- a/build.sh
+++ b/build.sh
@@ -1,5 +1,7 @@
 #!/bin/sh
 
+set -e
+
 PROJECT="sindri"
 VERSION="dev-$(date -u '+%Y-%m-%d')-$(git rev-parse --short HEAD)"
 
diff --git a/fmt.sh b/fmt.sh
index 072748d..c89001d 100755
--- a/fmt.sh
+++ b/fmt.sh
@@ -1,3 +1,6 @@
 #!/bin/sh
 
-odinfmt -w src/
+set -e
+
+odinfmt -w src/ > /dev/null
+odinfmt -w tests/ > /dev/null
diff --git a/scripts/pre-commit b/scripts/pre-commit
index 3dd43ff..c88d146 100755
--- a/scripts/pre-commit
+++ b/scripts/pre-commit
@@ -2,5 +2,17 @@
 
 SCRIPT_DIR=$(CDPATH='' cd -- "$(dirname -- "$0")" && pwd)
 
+git stash push --keep-index --quiet
+
 "$SCRIPT_DIR/../fmt.sh"
+
+if ! git diff --quiet; then
+	echo "Formatting changed staged files; commit aborted."
+	git checkout -- "$SCRIPT_DIR/.."
+	git stash pop --quiet
+	exit 1
+fi
+
 "$SCRIPT_DIR/../test.sh"
+
+git stash pop --quiet
diff --git a/tests/blabla.odin b/tests/blabla.odin
index a75f317..e1e8192 100644
--- a/tests/blabla.odin
+++ b/tests/blabla.odin
@@ -4,5 +4,5 @@ import "core:testing"
 
 @(test)
 foo :: proc(t: ^testing.T) {
-    testing.expect(t, 1 + 1 == 2, "pass")
+	testing.expect(t, 1 + 1 == 2, "pass")
 }