diff --git a/sio/executors/executor.py b/sio/executors/executor.py
index 3f73f11..58ddaf6 100644
--- a/sio/executors/executor.py
+++ b/sio/executors/executor.py
@@ -1,10 +1,10 @@
 from __future__ import absolute_import
 from sio.executors import common, interactive_common
-from sio.workers.executors import SupervisedExecutor
+from sio.workers.executors import RealTimeSio2JailExecutor
 
 
 def run(environ):
-    return common.run(environ, SupervisedExecutor())
+    return common.run(environ, RealTimeSio2JailExecutor())
 
 def interactive_run(environ):
-    return interactive_common.run(environ, SupervisedExecutor())
+    return interactive_common.run(environ, RealTimeSio2JailExecutor())
diff --git a/sio/workers/executors.py b/sio/workers/executors.py
index 61364fd..cdb60d4 100644
--- a/sio/workers/executors.py
+++ b/sio/workers/executors.py
@@ -604,8 +604,9 @@ class Sio2JailExecutor(SandboxExecutor):
     REAL_TIME_LIMIT_MULTIPLIER = 16
     REAL_TIME_LIMIT_ADDEND = 1000  # (in ms)
 
-    def __init__(self):
+    def __init__(self, measure_real_time=False):
         super(Sio2JailExecutor, self).__init__('sio2jail_exec-sandbox-1.4.4')
+        self.measure_real_time = measure_real_time
 
     def _execute(self, command, **kwargs):
         options = []
@@ -614,23 +615,30 @@ def _execute(self, command, **kwargs):
             '--memory-limit',
             str(kwargs['mem_limit'] or self.DEFAULT_MEMORY_LIMIT) + 'K',
         ]
-        options += [
-            '--instruction-count-limit',
-            str(
-                (kwargs['time_limit'] or self.DEFAULT_TIME_LIMIT)
-                * self.INSTRUCTIONS_PER_VIRTUAL_SECOND
-                // 1000
-            ),
-        ]
-        options += [
-            '--rtimelimit',
-            str(
-                (kwargs['time_limit'] or self.DEFAULT_TIME_LIMIT)
-                * self.REAL_TIME_LIMIT_MULTIPLIER
-                + self.REAL_TIME_LIMIT_ADDEND
-            )
-            + 'ms',
-        ]
+        if self.measure_real_time:
+            options += [
+                '--rtimelimit',
+                str(kwargs['time_limit'] or self.DEFAULT_TIME_LIMIT) + 'ms',
+            ]
+            options += ['-o', 'oireal']
+        else:
+            options += [
+                '--instruction-count-limit',
+                str(
+                    (kwargs['time_limit'] or self.DEFAULT_TIME_LIMIT)
+                    * self.INSTRUCTIONS_PER_VIRTUAL_SECOND
+                    // 1000
+                ),
+            ]
+            options += [
+                '--rtimelimit',
+                str(
+                    (kwargs['time_limit'] or self.DEFAULT_TIME_LIMIT)
+                    * self.REAL_TIME_LIMIT_MULTIPLIER
+                    + self.REAL_TIME_LIMIT_ADDEND
+                )
+                + 'ms',
+            ]
         options += [
             '--output-limit',
             str(kwargs['output_limit'] or self.DEFAULT_OUTPUT_LIMIT) + 'K',
@@ -704,6 +712,13 @@ def _execute(self, command, **kwargs):
 
         return renv
 
+class RealTimeSio2JailExecutor(Sio2JailExecutor):
+    """ Similiar to Sio2JailExecutor, with the exception of measuring real time
+        instead of the number of instructions executed.
+    """
+    def __init__(self):
+        super(RealTimeSio2JailExecutor, self).__init__(measure_real_time=True)
+
 
 class SupervisedExecutor(_SIOSupervisedExecutor):
     """Executes program in supervised mode.
diff --git a/sio/workers/file_runners.py b/sio/workers/file_runners.py
index a2f330c..813eaad 100644
--- a/sio/workers/file_runners.py
+++ b/sio/workers/file_runners.py
@@ -3,6 +3,7 @@
     UnprotectedExecutor,
     DetailedUnprotectedExecutor,
     Sio2JailExecutor,
+    RealTimeSio2JailExecutor,
     SupervisedExecutor,
     PRootExecutor,
 )
@@ -95,6 +96,7 @@ class Executable(LanguageModeWrapper):
         DetailedUnprotectedExecutor,
         PRootExecutor,
         Sio2JailExecutor,
+        RealTimeSio2JailExecutor,
         SupervisedExecutor,
     )
 
diff --git a/sio/workers/test/sources/openrw.c b/sio/workers/test/sources/openrw.c
index 80b5348..6cea9ec 100644
--- a/sio/workers/test/sources/openrw.c
+++ b/sio/workers/test/sources/openrw.c
@@ -1,4 +1,5 @@
 #include <fcntl.h>
+#include <unistd.h>
 
 int main() {
     char ch[] = "1337";
diff --git a/sio/workers/test/test_executors.py b/sio/workers/test/test_executors.py
index e0df4cd..e6f27c4 100644
--- a/sio/workers/test/test_executors.py
+++ b/sio/workers/test/test_executors.py
@@ -34,6 +34,7 @@
     SandboxExecutor,
     SupervisedExecutor,
     Sio2JailExecutor,
+    RealTimeSio2JailExecutor,
     ExecError,
 )
 from sio.workers.file_runners import get_file_runner
@@ -137,7 +138,10 @@ def fail(*args, **kwargs):
 SANDBOXED_CHECKING_EXECUTORS = [SupervisedExecutor]
 
 if not NO_SIO2JAIL_TESTS:
-    SANDBOXED_CHECKING_EXECUTORS.append(Sio2JailExecutor)
+    SANDBOXED_CHECKING_EXECUTORS += (
+        Sio2JailExecutor,
+        RealTimeSio2JailExecutor,
+    )
 
 # Status helpers
 def res_ok(env):
@@ -290,8 +294,12 @@ def _make_common_time_limiting_cases():
                     yield '/time_verylong.java', 5000, executor(), res_ok
 
             if issubclass(executor, Sio2JailExecutor):
-                yield "/time_s2j_200ms.c", 100, executor(), res_tle
-                yield "/time_s2j_200ms.c", 1000, executor(), res_ok
+                if issubclass(executor, RealTimeSio2JailExecutor):
+                    yield "/time_verylong.c", 100, executor(), res_tle
+                    yield "/time_verylong.c", 10000, executor(), res_ok
+                else:
+                    yield "/time_s2j_200ms.c", 100, executor(), res_tle
+                    yield "/time_s2j_200ms.c", 1000, executor(), res_ok
 
 @pytest.mark.parametrize(
     "source,time_limit,executor,callback",
@@ -794,22 +802,17 @@ def syscall_limit(env):
         in_('syscalls', env['result_string'])
 
     checking_executors = CHECKING_EXECUTORS
+    if ENABLE_SANDBOXES and not NO_SIO2JAIL_TESTS:
+        checking_executors.append(RealTimeSio2JailExecutor)
 
     for executor in checking_executors:
-        yield [
-            '/time_infinite.c',
-            executor(),
-            real_tle,
-            {'real_time_limit': 1000, 'time_limit': 10000},
-        ]
-
-    for executor in CHECKING_EXECUTORS:
-        yield [
-            '/iospam.c',
-            executor(),
-            real_tle,
-            {'real_time_limit': 1000, 'time_limit': 10000},
-        ]
+        for file in ('/time_infinite.c', '/iospam.c'):
+            yield [
+                file,
+                executor(),
+                real_tle,
+                {'real_time_limit': 1000, 'time_limit': 10000},
+            ]
 
 
 @pytest.mark.parametrize(