diff --git a/projects/heasarc.gsfc.nasa.gov/cfitsio/package.yml b/projects/heasarc.gsfc.nasa.gov/cfitsio/package.yml
index 1a8c04c4..0c163d89 100644
--- a/projects/heasarc.gsfc.nasa.gov/cfitsio/package.yml
+++ b/projects/heasarc.gsfc.nasa.gov/cfitsio/package.yml
@@ -14,18 +14,24 @@ dependencies:
     zlib.net: '*'
 
 build:
-  script: |
-    ./configure $ARGS
-    make shared
-    make install
+  script:
+    - ./configure $ARGS
+    - make shared
+    - make install
   env:
     ARGS:
       - --prefix="{{ prefix }}"
       - --enable-reentrant
 
 test:
-  script: |
-    cc testprog.c -o testprog -lcfitsio
-    ./testprog > testprog.lis
-    cmp testprog.lis testprog.out
-    cmp testprog.fit testprog.std
+  - cc testprog.c -o testprog -lcfitsio
+  - ./testprog > testprog.lis
+  - run: |
+      cmp testprog.lis testprog.out
+      cmp testprog.fit testprog.std
+    if: darwin
+  # archlinux doesn't have cmp or diff, but it has sha256sum
+  - run: |
+      test "$(sha256sum testprog.lis | awk '{print $1}')" = "$(sha256sum testprog.out | awk '{print $1}')"
+      test "$(sha256sum testprog.fit | awk '{print $1}')" = "$(sha256sum testprog.std | awk '{print $1}')"
+    if: linux