diff --git a/cwltool/draft2tool.py b/cwltool/draft2tool.py
index 64213d067..5a52836c2 100644
--- a/cwltool/draft2tool.py
+++ b/cwltool/draft2tool.py
@@ -21,7 +21,9 @@
 from .errors import WorkflowException
 from .job import JobBase, CommandLineJob, DockerCommandLineJob
 from .pathmapper import PathMapper, get_listing, trim_listing
-from .process import Process, shortname, uniquename, normalizeFilesDirs, compute_checksums, _logger_validation_warnings
+from .process import (Process, shortname, uniquename, normalizeFilesDirs,
+                      compute_checksums, _logger_validation_warnings,
+                      UnsupportedRequirement)
 from .stdfsaccess import StdFsAccess
 from .utils import aslist
 
@@ -177,6 +179,11 @@ def makeJobRunner(self, use_container=True):  # type: (Optional[bool]) -> JobBas
         if dockerReq and use_container:
             return DockerCommandLineJob()
         else:
+            for t in reversed(self.requirements):
+                if t["class"] == "DockerRequirement":
+                    raise UnsupportedRequirement(
+                        "--no-container, but this CommandLineTool has "
+                        "DockerRequirement under 'requirements'.")
             return CommandLineJob()
 
     def makePathMapper(self, reffiles, stagedir, **kwargs):
diff --git a/cwltool/job.py b/cwltool/job.py
index 8cc279508..918522be8 100644
--- a/cwltool/job.py
+++ b/cwltool/job.py
@@ -18,7 +18,8 @@
 from .docker_uid import docker_vm_uid
 from .errors import WorkflowException
 from .pathmapper import PathMapper
-from .process import get_feature, empty_subtree, stageFiles
+from .process import (get_feature, empty_subtree, stageFiles,
+                      UnsupportedRequirement)
 
 _logger = logging.getLogger("cwltool")
 
@@ -335,9 +336,12 @@ def run(self, pull_image=True, rm_container=True,
         except Exception as e:
             _logger.debug("Docker error", exc_info=True)
             if docker_is_req:
-                raise WorkflowException("Docker is required to run this tool: %s" % e)
+                raise UnsupportedRequirement(
+                    "Docker is required to run this tool: %s" % e)
             else:
-                raise WorkflowException("Docker is not available for this tool, try --no-container to disable Docker: %s" % e)
+                raise WorkflowException(
+                    "Docker is not available for this tool, try --no-container"
+                    " to disable Docker: %s" % e)
 
         self._setup()
 
diff --git a/cwltool/process.py b/cwltool/process.py
index 02c5684c1..4b0942e52 100644
--- a/cwltool/process.py
+++ b/cwltool/process.py
@@ -530,11 +530,6 @@ def _init_job(self, joborder, **kwargs):
         builder.mutation_manager = kwargs.get("mutation_manager")
 
         dockerReq, is_req = self.get_requirement("DockerRequirement")
-
-        if dockerReq and is_req and not kwargs.get("use_container"):
-            raise WorkflowException(
-                "Document has DockerRequirement under 'requirements' but use_container is false.  DockerRequirement must be under 'hints' or use_container must be true.")
-
         builder.make_fs_access = kwargs.get("make_fs_access") or StdFsAccess
         builder.fs_access = builder.make_fs_access(kwargs["basedir"])