diff --git a/cmd/jsonnetfmt.cpp b/cmd/jsonnetfmt.cpp
index 54932bf15..8b7c90322 100644
--- a/cmd/jsonnetfmt.cpp
+++ b/cmd/jsonnetfmt.cpp
@@ -231,6 +231,7 @@ int main(int argc, const char **argv)
         std::string output_file = config.outputFile;
 
         if (config.fmtInPlace || config.fmtTest) {
+            bool changed_files = false;
             assert(config.inputFiles.size() >= 1);
             for (std::string &inputFile : config.inputFiles) {
                 if (config.fmtInPlace) {
@@ -269,8 +270,10 @@ int main(int argc, const char **argv)
                     bool ok = output == input;
                     jsonnet_realloc(vm, output, 0);
                     if (!ok) {
-                        jsonnet_destroy(vm);
-                        return 2;
+                        if (inputFile != "-" && !config.filenameIsCode) {
+                            std::cout << inputFile << std::endl;
+                        }
+                        changed_files = true;
                     }
                 } else {
                     // Write output Jsonnet only if there is a difference between input and output
@@ -282,11 +285,19 @@ int main(int argc, const char **argv)
                             jsonnet_destroy(vm);
                             return EXIT_FAILURE;
                         }
+                        if (inputFile != "-" && !config.filenameIsCode) {
+                            std::cout << inputFile << std::endl;
+                        }
                     } else {
                         jsonnet_realloc(vm, output, 0);
                     }
                 }
             }
+
+            if (config.fmtTest && changed_files) {
+                jsonnet_destroy(vm);
+                return 2;
+            }
         } else {
             assert(config.inputFiles.size() == 1);
             // Read input file.
diff --git a/test_cmd/fmt_inplace.golden.stdout b/test_cmd/fmt_inplace.golden.stdout
new file mode 100644
index 000000000..89c5bad61
--- /dev/null
+++ b/test_cmd/fmt_inplace.golden.stdout
@@ -0,0 +1 @@
+out/fmt_inplace/test_badfmt.jsonnet
diff --git a/test_cmd/fmt_simple_test1.golden.stdout b/test_cmd/fmt_simple_test1.golden.stdout
new file mode 100644
index 000000000..e69de29bb
diff --git a/test_cmd/fmt_simple_test2.golden.stdout b/test_cmd/fmt_simple_test2.golden.stdout
new file mode 100644
index 000000000..e69de29bb
diff --git a/test_cmd/fmt_simple_test3.golden.stdout b/test_cmd/fmt_simple_test3.golden.stdout
new file mode 100644
index 000000000..e69de29bb
diff --git a/test_cmd/fmt_simple_test4.golden.stdout b/test_cmd/fmt_simple_test4.golden.stdout
new file mode 100644
index 000000000..f77a0b6cb
--- /dev/null
+++ b/test_cmd/fmt_simple_test4.golden.stdout
@@ -0,0 +1 @@
+test_badfmt.jsonnet
diff --git a/test_cmd/run_cmd_tests.sh b/test_cmd/run_cmd_tests.sh
index 5d6350754..d8c72e492 100755
--- a/test_cmd/run_cmd_tests.sh
+++ b/test_cmd/run_cmd_tests.sh
@@ -27,6 +27,8 @@ source "${DIR}/cmd_tests.source"
 OUT_DIR=$(mktemp -d)
 trap "rm -rf -- ${OUT_DIR}" EXIT INT TERM
 
+>&2 echo "output dir: ${OUT_DIR}"
+
 pushd "${DIR}"
 
 [[ -d "${OUT_DIR}" ]] || {
@@ -174,17 +176,25 @@ if do_fmt_test "fmt_out" 0 -e "{ a: 1, b: 2, c: 3 }" -o "${OUT_DIR}/fmt_out/cust
 fi
 do_fmt_test "fmt_double_dash" 0 -e -- -1
 
-if mkdir -p "${OUT_DIR}/fmt_inplace" && cp "test.jsonnet" "${OUT_DIR}/fmt_inplace/test.jsonnet"; then
+do_fmt_test "fmt_simple_test1" 0 --test "test.jsonnet"
+do_fmt_test "fmt_simple_test2" 2 --test -e "{a:1,b:2,c:3}"
+do_fmt_test "fmt_simple_test3" 0 --test -e $'42\n'
+do_fmt_test "fmt_simple_test4" 2 --test "test.jsonnet" "test_badfmt.jsonnet"
+
+SED_STDOUT="${SED_REPLACE_OUT_DIR}"
+if mkdir -p "${OUT_DIR}/fmt_inplace" && cp "test.jsonnet" "test_badfmt.jsonnet" "${OUT_DIR}/fmt_inplace/"; then
     # Test jsonnetfmt in-place modifications
-    do_fmt_test "fmt_inplace" 0 -i "${OUT_DIR}/fmt_inplace/test.jsonnet"
     check_file "fmt_inplace" "${OUT_DIR}/fmt_inplace/test.jsonnet" "fmt_simple_out.golden.custom_output"
     # Verify that running jsonnetfmt on an already formatted file does not change timesetamps
     touch -m -t 199108252057.08 "${OUT_DIR}/fmt_inplace/test.jsonnet"
+    touch -m -t 199108252057.08 "${OUT_DIR}/fmt_inplace/test_badfmt.jsonnet"
     stat -c '%y' "${OUT_DIR}/fmt_inplace/test.jsonnet" > "${OUT_DIR}/fmt_inplace/stat_mod_time_before.txt"
-    do_fmt_test "fmt_inplace" 0 -i "${OUT_DIR}/fmt_inplace/test.jsonnet"
+    do_fmt_test "fmt_inplace" 0 -i \
+        "${OUT_DIR}/fmt_inplace/test.jsonnet" "${OUT_DIR}/fmt_inplace/test_badfmt.jsonnet"
     stat -c '%y' "${OUT_DIR}/fmt_inplace/test.jsonnet" > "${OUT_DIR}/fmt_inplace/stat_mod_time_after.txt"
     check_file "fmt_inplace" "${OUT_DIR}/fmt_inplace/stat_mod_time_before.txt" "${OUT_DIR}/fmt_inplace/stat_mod_time_after.txt"
 fi
+unset -v SED_STDOUT
 
 fi
 
diff --git a/test_cmd/test_badfmt.jsonnet b/test_cmd/test_badfmt.jsonnet
new file mode 100644
index 000000000..8569c4df1
--- /dev/null
+++ b/test_cmd/test_badfmt.jsonnet
@@ -0,0 +1,3 @@
+{a:1, b:
+
+2,['c']:3}