diff --git a/check.py b/check.py
index 3bf3bafcf5b..dddddb424f0 100755
--- a/check.py
+++ b/check.py
@@ -189,10 +189,10 @@ def run_opt_test(wast, stdout=None):
     support.run_command(cmd, stdout=stdout)
 
 
-def check_expected(actual, expected, stdout=None):
+def check_expected(actual, expected):
     if expected and os.path.exists(expected):
         expected = open(expected).read()
-        print('       (using expected output)', file=stdout)
+        shared.verbose_log('       (using expected output)')
         actual = actual.strip()
         expected = expected.strip()
         if actual != expected:
@@ -229,13 +229,13 @@ def run_one_spec_test(wast: Path, stdout=None):
         actual = run_spec_test(str(wast), stdout=stdout)
     except Exception as e:
         if ('wasm-validator error' in str(e) or 'error: ' in str(e)) and '.fail.' in test_name:
-            print('<< test failed as expected >>', file=stdout)
+            shared.verbose_log('<< test failed as expected >>')
             return  # don't try all the binary format stuff TODO
         else:
             shared.fail_with_error(str(e))
             raise
 
-    check_expected(actual, expected, stdout=stdout)
+    check_expected(actual, expected)
 
     if not is_splittable(wast):
         return
@@ -249,12 +249,12 @@ def run_one_spec_test(wast: Path, stdout=None):
             if not module:
                 # Skip any initial assertions that don't have a module
                 continue
-            print(f'        testing split module {i}', file=stdout)
+            shared.verbose_log(f'        testing split module {i}')
             split_name = base_name + f'_split{i}.wast'
             support.write_wast(split_name, module)
             run_opt_test(split_name, stdout=stdout)    # also that our optimizer doesn't break on it
 
-            result_wast_file = shared.binary_format_check(split_name, verify_final_result=False, base_name=base_name, stdout=stdout)
+            result_wast_file = shared.binary_format_check(split_name, verify_final_result=False, base_name=base_name)
             with open(result_wast_file) as f:
                 result_wast = f.read()
                 # add the asserts, and verify that the test still passes
@@ -262,7 +262,7 @@ def run_one_spec_test(wast: Path, stdout=None):
 
     # compare all the outputs to the expected output
     actual = run_spec_test(transformed_path, stdout=stdout)
-    check_expected(actual, os.path.join(shared.get_test_dir('spec'), 'expected-output', test_name + '.log'), stdout=stdout)
+    check_expected(actual, os.path.join(shared.get_test_dir('spec'), 'expected-output', test_name + '.log'))
 
 
 def run_spec_test_with_wrapped_stdout(wast: Path):
diff --git a/scripts/test/shared.py b/scripts/test/shared.py
index 4786bf2c755..d97bafb98a7 100644
--- a/scripts/test/shared.py
+++ b/scripts/test/shared.py
@@ -97,6 +97,9 @@ def parse_args(args):
         action='store_false', default=True,
         help='Disables the automatic selection of important initial contents '
              'in fuzzer.')
+    parser.add_argument(
+        '--verbose', action='store_true', default=False,
+        help='Enables verbose logging.')
 
     return parser.parse_args(args)
 
@@ -118,6 +121,11 @@ def print_heading(msg):
     print(f'[ {msg} ]')
 
 
+def verbose_log(*args, **kwargs):
+    if options.verbose:
+        print(*args, **kwargs)
+
+
 # setup
 
 # Locate Binaryen build artifacts directory (bin/ by default)
@@ -466,22 +474,22 @@ def _can_run_spec_test(test):
 # check utilities
 
 
-def binary_format_check(wast, verify_final_result=True, base_name=None, stdout=None):
+def binary_format_check(wast, verify_final_result=True, base_name=None):
     # checks we can convert the wast to binary and back
 
     as_file = f"{base_name}-a.wasm" if base_name is not None else "a.wasm"
     disassembled_file = f"{base_name}-ab.wast" if base_name is not None else "ab.wast"
 
-    print('         (binary format check)', file=stdout)
+    verbose_log('         (binary format check)')
     cmd = WASM_AS + [wast, '-o', as_file, '-all', '-g']
-    print('            ', ' '.join(cmd), file=stdout)
+    verbose_log('            ', ' '.join(cmd))
     if os.path.exists(as_file):
         os.unlink(as_file)
     subprocess.check_call(cmd, stdout=subprocess.PIPE)
     assert os.path.exists(as_file)
 
     cmd = WASM_DIS + [as_file, '-o', disassembled_file, '-all']
-    print('            ', ' '.join(cmd), file=stdout)
+    verbose_log('            ', ' '.join(cmd))
     if os.path.exists(disassembled_file):
         os.unlink(disassembled_file)
     subprocess.check_call(cmd, stdout=subprocess.PIPE)
@@ -489,7 +497,7 @@ def binary_format_check(wast, verify_final_result=True, base_name=None, stdout=N
 
     # make sure it is a valid wast
     cmd = WASM_OPT + [disassembled_file, '-all', '-q']
-    print('            ', ' '.join(cmd), file=stdout)
+    verbose_log('            ', ' '.join(cmd))
     subprocess.check_call(cmd, stdout=subprocess.PIPE)
 
     if verify_final_result: