diff --git a/tests/interactive.fish b/tests/interactive.fish
index 933749446..f6a05a12b 100644
--- a/tests/interactive.fish
+++ b/tests/interactive.fish
@@ -69,11 +69,11 @@ function test_file
         say red "fail"
         if test $out_status -ne 0
             say yellow "Output differs for file $file. Diff follows:"
-            colordiff -u $file.tmp.out $file.out
+            colordiff -u $file.out $file.tmp.out
         end
         if test $err_status -ne 0
             say yellow "Error output differs for file $file. Diff follows:"
-            colordiff -u $file.tmp.err $file.err
+            colordiff -u $file.err $file.tmp.err
         end
         if test $exit_status -ne 0
             say yellow "Exit status differs for file $file."
diff --git a/tests/invocation.sh b/tests/invocation.sh
index 8ced43e4e..728636ca4 100755
--- a/tests/invocation.sh
+++ b/tests/invocation.sh
@@ -245,10 +245,10 @@ test_file() (
     mv -f "${test_stderr}.new" "${test_stderr}"
 
     # Check the results
-    if ! diff "${test_stdout}" "${want_stdout}" >/dev/null 2>/dev/null ; then
+    if ! diff "${want_stdout}" "${test_stdout}" >/dev/null 2>/dev/null ; then
         out_status=1
     fi
-    if ! diff "${test_stderr}" "${want_stderr}" >/dev/null 2>/dev/null ; then
+    if ! diff "${want_stderr}" "${test_stderr}" >/dev/null 2>/dev/null ; then
         err_status=1
     fi
 
@@ -264,11 +264,11 @@ test_file() (
 
         if [ "$out_status" != '0' ] ; then
             say "$term_yellow" "Output differs for file $file. Diff follows:"
-            "$difftool" -u "${test_stdout}" "${want_stdout}"
+            "$difftool" -u "${want_stdout}" "${test_stdout}"
         fi
         if [ "$err_status" != '0' ] ; then
             say "$term_yellow" "Error output differs for file $file. Diff follows:"
-            "$difftool" -u "${test_stderr}" "${want_stderr}"
+            "$difftool" -u  "${want_stderr}" "${test_stderr}"
         fi
         rc=1
     fi
diff --git a/tests/test.fish b/tests/test.fish
index 0711e0933..62025fe0d 100644
--- a/tests/test.fish
+++ b/tests/test.fish
@@ -55,11 +55,11 @@ function test_file
         say red "fail"
         if test $out_status -ne 0
             say yellow "Output differs for file $file. Diff follows:"
-            colordiff -u $base.tmp.out $base.out
+            colordiff -u $base.out $base.tmp.out
         end
         if test $err_status -ne 0
             say yellow "Error output differs for file $file. Diff follows:"
-            colordiff -u $base.tmp.err $base.err
+            colordiff -u $base.err $base.tmp.err
         end
         if test $exit_status -ne 0
             say yellow "Exit status differs for file $file."