--- a/testing/mozharness/mozharness/base/script.py
+++ b/testing/mozharness/mozharness/base/script.py
@@ -1451,16 +1451,24 @@ class ScriptMixin(PlatformMixin):
                         """Avoid losing the final lines of the log?"""
                         loop = False
                     while True:
                         line = p.stdout.readline()
                         if not line:
                             break
                         parser.add_lines(line)
                 returncode = p.returncode
+        except KeyboardInterrupt:
+            level = error_level
+            if halt_on_failure:
+                level = FATAL
+            self.log("Process interrupted by the user, killing process with pid %s" % p.pid,
+                     level=level)
+            p.kill()
+            return -1
         except OSError, e:
             level = error_level
             if halt_on_failure:
                 level = FATAL
             self.log('caught OS error %s: %s while running %s' % (e.errno,
                      e.strerror, command), level=level)
             return -1