diff --git a/course/admin.py b/course/admin.py
index a025637283e76a3971ddc64505d3ff0d9dab9764..ace25a802a41fd5c869d0bf336fb645281b57e46 100644
--- a/course/admin.py
+++ b/course/admin.py
@@ -25,7 +25,7 @@ THE SOFTWARE.
 import six
 
 from django.utils.translation import (
-        ugettext_lazy as _, string_concat, pgettext)
+        ugettext_lazy as _, pgettext)
 from django.contrib import admin
 
 from course.models import (
@@ -41,6 +41,7 @@ from course.models import (
         GradingOpportunity, GradeChange, InstantMessage,
         Exam, ExamTicket)
 from django import forms
+from relate.utils import string_concat
 from course.enrollment import (approve_enrollment, deny_enrollment)
 from course.constants import (
         participation_permission as pperm,
diff --git a/course/analytics.py b/course/analytics.py
index db42be5ca2678595433b7e2014e76896db800d26..508e5116b7a51a09dd1700598696e375db4a114e 100644
--- a/course/analytics.py
+++ b/course/analytics.py
@@ -26,7 +26,7 @@ THE SOFTWARE.
 
 
 import six
-from django.utils.translation import ugettext as _, pgettext, string_concat
+from django.utils.translation import ugettext as _, pgettext
 from django.shortcuts import (  # noqa
         render, get_object_or_404, redirect)
 from django.contrib.auth.decorators import login_required
@@ -408,6 +408,7 @@ def make_time_histogram(pctx, flow_id):
             course=pctx.course,
             flow_id=flow_id)
 
+    from relate.utils import string_concat
     hist = Histogram(
             num_log_bins=True,
             num_bin_title_formatter=(
diff --git a/course/auth.py b/course/auth.py
index 30da4277f6b426a50396ec853b50ebf08055da48..229bcfeffbf3f2cfbf29d2adfc01637754b7e463 100644
--- a/course/auth.py
+++ b/course/auth.py
@@ -25,7 +25,7 @@ THE SOFTWARE.
 """
 
 from typing import cast
-from django.utils.translation import ugettext_lazy as _, string_concat
+from django.utils.translation import ugettext_lazy as _
 from django.shortcuts import (  # noqa
         render, get_object_or_404, redirect, resolve_url)
 from django.contrib import messages
@@ -61,7 +61,7 @@ from course.constants import (
 from course.models import Participation, Course  # noqa
 from accounts.models import User
 
-from relate.utils import StyledForm, StyledModelForm
+from relate.utils import StyledForm, StyledModelForm, string_concat
 from django_select2.forms import ModelSelect2Widget
 
 if False:
diff --git a/course/calendar.py b/course/calendar.py
index 3fbfe8c3b8b1d0059df34b5a9df9905a106b0d6b..7a06232f7526378dd59c98e4ff9c7321488b86b5 100644
--- a/course/calendar.py
+++ b/course/calendar.py
@@ -28,7 +28,7 @@ import six
 from six.moves import range
 
 from django.utils.translation import (
-        ugettext_lazy as _, pgettext_lazy, string_concat)
+        ugettext_lazy as _, pgettext_lazy)
 from django.contrib.auth.decorators import login_required
 from course.utils import course_view, render_course_page
 from django.core.exceptions import PermissionDenied, ObjectDoesNotExist
@@ -41,7 +41,7 @@ from crispy_forms.layout import Submit
 import datetime
 from bootstrap3_datetime.widgets import DateTimePicker
 
-from relate.utils import StyledForm, as_local_time
+from relate.utils import StyledForm, as_local_time, string_concat
 from course.constants import (
         participation_permission as pperm,
         )
diff --git a/course/enrollment.py b/course/enrollment.py
index 12adfd97f51a224495022ff7dea2b0ce8d0a2691..6e2c914666207d1be85a8e3109d38cb8fe0ad12c 100644
--- a/course/enrollment.py
+++ b/course/enrollment.py
@@ -28,8 +28,7 @@ from six.moves import intern
 
 from django.utils.translation import (
         ugettext_lazy as _,
-        pgettext,
-        string_concat)
+        pgettext)
 from django.shortcuts import (  # noqa
         render, get_object_or_404, redirect)
 from django.contrib import messages
@@ -65,7 +64,7 @@ from course.auth import UserSearchWidget
 
 from course.utils import course_view, render_course_page
 
-from relate.utils import StyledForm, StyledModelForm
+from relate.utils import StyledForm, StyledModelForm, string_concat
 
 from pytools.lex import RE as REBase  # noqa
 
diff --git a/course/exam.py b/course/exam.py
index 2470061d4c60dc6b54e40ed03de850539ec85f31..6cd666c7aa36962bc7b22c3f339f2ab3eae197a8 100644
--- a/course/exam.py
+++ b/course/exam.py
@@ -29,8 +29,7 @@ import six
 from django.contrib.auth import get_user_model
 import django.forms as forms
 from django.utils.translation import (
-        ugettext, ugettext_lazy as _, string_concat,
-        pgettext)
+        ugettext, ugettext_lazy as _, pgettext)
 from django.shortcuts import (  # noqa
         render, get_object_or_404, redirect)
 from django.core.exceptions import (  # noqa
@@ -58,7 +57,7 @@ from course.constants import (
         participation_permission as pperm)
 from course.views import get_now_or_fake_time
 
-from relate.utils import StyledForm
+from relate.utils import StyledForm, string_concat
 
 
 # {{{ mypy
diff --git a/course/flow.py b/course/flow.py
index c7e8bbebc81f5c32c14708ce2b237286862d7bcc..3d7476d68b1d65b6aeee056b622e2209a477d6ea 100644
--- a/course/flow.py
+++ b/course/flow.py
@@ -26,7 +26,7 @@ THE SOFTWARE.
 
 from django.utils import six
 from django.utils.translation import (
-        ugettext, ugettext_lazy as _, string_concat)
+        ugettext, ugettext_lazy as _)
 from django.utils.functional import lazy
 from django.shortcuts import (  # noqa
         render, get_object_or_404, redirect)
@@ -48,7 +48,7 @@ from crispy_forms.helper import FormHelper
 
 from relate.utils import (
         StyledForm, local_now, as_local_time,
-        format_datetime_local)
+        format_datetime_local, string_concat)
 from crispy_forms.layout import Submit
 from django_select2.forms import Select2Widget
 
diff --git a/course/grades.py b/course/grades.py
index 012a474cb0f65f808f9412dd3659b994c3bd270e..8523337450808607919742b7817164d90da4d5cb 100644
--- a/course/grades.py
+++ b/course/grades.py
@@ -30,7 +30,7 @@ import six
 from typing import cast
 
 from django.utils.translation import (
-        ugettext_lazy as _, pgettext_lazy, ugettext, string_concat)
+        ugettext_lazy as _, pgettext_lazy, ugettext)
 from django.shortcuts import (  # noqa
         render, redirect, get_object_or_404)
 from django.contrib import messages  # noqa
@@ -43,7 +43,7 @@ from django.utils.timezone import now
 from django import http
 
 from django.urls import reverse
-from relate.utils import StyledForm, StyledModelForm
+from relate.utils import StyledForm, StyledModelForm, string_concat
 from crispy_forms.layout import Submit
 from bootstrap3_datetime.widgets import DateTimePicker
 
diff --git a/course/models.py b/course/models.py
index 6b4c0f32d21fcb0d26d53792fb26ffae2dbc87fc..d2de46769930c290e6663864133e0c1ce3c91965 100644
--- a/course/models.py
+++ b/course/models.py
@@ -33,13 +33,14 @@ from django.utils.timezone import now
 from django.urls import reverse
 from django.core.exceptions import ValidationError, ObjectDoesNotExist
 from django.utils.translation import (
-        ugettext_lazy as _, pgettext_lazy, string_concat)
+        ugettext_lazy as _, pgettext_lazy)
 from django.core.validators import RegexValidator
 from django.db.models.signals import post_save
 from django.dispatch import receiver
 
 from django.conf import settings
 
+from relate.utils import string_concat
 from course.constants import (  # noqa
         user_status, USER_STATUS_CHOICES,
         participation_status, PARTICIPATION_STATUS_CHOICES,
diff --git a/course/page/base.py b/course/page/base.py
index a8259034145ed22cdea1c17516dd98bd8de25826..4bc5c7eb450d9bac9f36cbb6d009a38beff04471 100644
--- a/course/page/base.py
+++ b/course/page/base.py
@@ -30,14 +30,13 @@ import django.forms as forms
 
 from course.validation import validate_struct, ValidationError
 from course.constants import MAX_EXTRA_CREDIT_FACTOR
-from relate.utils import StyledForm, Struct
+from relate.utils import StyledForm, Struct, string_concat
 from django.forms import ValidationError as FormValidationError
 from django.utils.safestring import mark_safe
 from django.utils.functional import lazy
 from django.utils.translation import (
         ugettext_lazy as _,
         ugettext,
-        string_concat,
         )
 from django.utils import translation
 from django.conf import settings
diff --git a/course/page/choice.py b/course/page/choice.py
index b59669c86293e660410b347d9cf0864b7d05d8ab..edaa2ee9610c1d4a21052e14fbd57d17b103aa8f 100644
--- a/course/page/choice.py
+++ b/course/page/choice.py
@@ -29,9 +29,9 @@ from six.moves import range
 import django.forms as forms
 from django.utils.safestring import mark_safe
 from django.utils.translation import (
-        ugettext_lazy as _, ugettext, string_concat)
+        ugettext_lazy as _, ugettext)
 
-from relate.utils import StyledForm
+from relate.utils import StyledForm, string_concat
 from course.page.base import (
         AnswerFeedback, PageBaseWithTitle, PageBaseWithValue, markup_to_html)
 from course.content import remove_prefix
diff --git a/course/page/code.py b/course/page/code.py
index 7933a2364e9a4484d9de3f5308107365fe31df56..520fa22fb687d59c67bb05442f28b1249b7e64b7 100644
--- a/course/page/code.py
+++ b/course/page/code.py
@@ -30,11 +30,11 @@ from course.validation import ValidationError
 import django.forms as forms
 from django.core.exceptions import ObjectDoesNotExist
 from django.utils.html import escape
-from django.utils.translation import ugettext as _, string_concat
+from django.utils.translation import ugettext as _
 from django.utils import translation
 from django.conf import settings
 
-from relate.utils import StyledForm
+from relate.utils import StyledForm, string_concat
 from course.page.base import (
         PageBaseWithTitle, markup_to_html, PageBaseWithValue,
         PageBaseWithHumanTextFeedback,
diff --git a/course/page/inline.py b/course/page/inline.py
index 281b1e5c4c463ac4a8ba2e0aa0b7d2d3b64e25eb..32ecb33445b9e5a777af625ebc009e010c3d8ccd 100644
--- a/course/page/inline.py
+++ b/course/page/inline.py
@@ -26,13 +26,13 @@ THE SOFTWARE.
 
 
 from django.utils.translation import (
-        ugettext_lazy as _, ugettext, string_concat)
+        ugettext_lazy as _, ugettext)
 from django.utils.safestring import mark_safe
 from course.validation import validate_struct, validate_markup, ValidationError
 from course.content import remove_prefix
 import django.forms as forms
 
-from relate.utils import Struct, StyledInlineForm
+from relate.utils import Struct, StyledInlineForm, string_concat
 from course.page.base import (
         AnswerFeedback, PageBaseWithValue, markup_to_html)
 
diff --git a/course/page/text.py b/course/page/text.py
index cb08c1b82cff344b940a996e73034baa5e560849..472f4fed25e96b31a415b4a8b2f0c3d5ae68ac96 100644
--- a/course/page/text.py
+++ b/course/page/text.py
@@ -27,11 +27,11 @@ THE SOFTWARE.
 
 import six
 from django.utils.translation import (
-        ugettext_lazy as _, ugettext, string_concat)
+        ugettext_lazy as _, ugettext)
 from course.validation import validate_struct, ValidationError
 import django.forms as forms
 
-from relate.utils import StyledForm, Struct
+from relate.utils import StyledForm, Struct, string_concat
 from course.page.base import (
         AnswerFeedback, PageBaseWithTitle, PageBaseWithValue, markup_to_html,
         PageBaseWithHumanTextFeedback, PageBaseWithCorrectAnswer,
diff --git a/course/page/upload.py b/course/page/upload.py
index 22e018d2717304d82524ee004c66921666026955..20c3e12ce49771b05718ca0ee7eab90c20cadf3c 100644
--- a/course/page/upload.py
+++ b/course/page/upload.py
@@ -26,7 +26,7 @@ THE SOFTWARE.
 
 
 import django.forms as forms
-from django.utils.translation import ugettext as _, ugettext_lazy, string_concat
+from django.utils.translation import ugettext as _, ugettext_lazy
 
 from course.page.base import (
         PageBaseWithTitle, PageBaseWithValue, PageBaseWithHumanTextFeedback,
@@ -34,7 +34,7 @@ from course.page.base import (
         markup_to_html)
 from course.validation import ValidationError
 
-from relate.utils import StyledForm
+from relate.utils import StyledForm, string_concat
 
 from crispy_forms.layout import Layout, Field
 
diff --git a/course/utils.py b/course/utils.py
index 122af4fde23dbf7905dffe5a3ab1949caaee306d..b8232ee5cfd148d2fdc140079049d07bd056ce75 100644
--- a/course/utils.py
+++ b/course/utils.py
@@ -34,10 +34,11 @@ from django.shortcuts import (  # noqa
 from django import http
 from django.core.exceptions import ObjectDoesNotExist
 from django.utils.translation import (
-        ugettext as _, string_concat, pgettext_lazy)
+        ugettext as _, pgettext_lazy)
 
 from codemirror import CodeMirrorTextarea, CodeMirrorJavascript
 
+from relate.utils import string_concat
 from course.content import (
         get_course_repo, get_flow_desc,
         parse_date_spec, get_course_commit_sha)
diff --git a/course/validation.py b/course/validation.py
index f3b51b1c8f20edcdb6d8c52b6063bc750887863a..f128cb1fc0d37bc8e6265dd6f50d7503d750eced 100644
--- a/course/validation.py
+++ b/course/validation.py
@@ -32,14 +32,14 @@ import sys
 from django.core.exceptions import ObjectDoesNotExist
 from django.utils.html import escape
 from django.utils.translation import (
-        ugettext_lazy as _, ugettext, string_concat)
+        ugettext_lazy as _, ugettext)
 from course.constants import (
         FLOW_SESSION_EXPIRATION_MODE_CHOICES,
         ATTRIBUTES_FILENAME,
         participation_permission as pperm)
 
 from course.content import get_repo_blob
-from relate.utils import Struct
+from relate.utils import Struct, string_concat
 
 # {{{ mypy
 
diff --git a/course/versioning.py b/course/versioning.py
index c392c7dae70a3ac8e8a84ba8301c1d1b96532b39..2a78565f7c7105a8f3482eda8543d5920f74793a 100644
--- a/course/versioning.py
+++ b/course/versioning.py
@@ -37,14 +37,13 @@ from django.utils.translation import (
         ugettext,
         pgettext,
         pgettext_lazy,
-        string_concat,
         )
 from django_select2.forms import Select2Widget
 from bootstrap3_datetime.widgets import DateTimePicker
 
 from django.db import transaction
 
-from relate.utils import StyledForm, StyledModelForm
+from relate.utils import StyledForm, StyledModelForm, string_concat
 from crispy_forms.layout import Submit
 
 from course.models import (
diff --git a/course/views.py b/course/views.py
index 6f1f14cd182bff5af861af60d582f4e66f2734ef..5128d3e2d8da2c05c3cd8f174882576f1e629fcf 100644
--- a/course/views.py
+++ b/course/views.py
@@ -40,7 +40,6 @@ from django.utils import six
 from django.utils.translation import (
         ugettext_lazy as _,
         ugettext,
-        string_concat,
         pgettext,
         pgettext_lazy,
         )
@@ -55,7 +54,7 @@ from django.views.decorators.cache import cache_control
 
 from crispy_forms.layout import Submit, Layout, Div
 
-from relate.utils import StyledForm, StyledModelForm
+from relate.utils import StyledForm, StyledModelForm, string_concat
 from bootstrap3_datetime.widgets import DateTimePicker
 
 from course.auth import get_pre_impersonation_user
diff --git a/relate/utils.py b/relate/utils.py
index 1c93bd93a0e0be892f4e67deb3438bd9b15e2d63..1c862b2519e267b2a5ed22bb568cd19aa116e161 100644
--- a/relate/utils.py
+++ b/relate/utils.py
@@ -36,6 +36,30 @@ from typing import Union
 if False:
     from typing import Text, List, Dict, Tuple, Optional, Any  # noqa
 
+# {{{ string_concat compatibility for Django >= 1.11
+
+try:
+    from django.utils.text import format_lazy
+except ImportError:
+    def _format_lazy(format_string, *args, **kwargs):
+        # type(Text, *Any, **Any) -> Text
+        """
+        Apply str.format() on 'format_string' where format_string, args,
+        and/or kwargs might be lazy.
+        """
+        return format_string.format(*args, **kwargs)
+
+    from django.utils.functional import lazy
+    format_lazy = lazy(_format_lazy, str)
+
+try:
+    from django.utils.translation import string_concat
+except ImportError:
+    def string_concat(*strings):
+        return format_lazy("{}" * len(strings), *strings)
+
+# }}}
+
 
 class StyledForm(forms.Form):
     def __init__(self, *args, **kwargs):
diff --git a/requirements.txt b/requirements.txt
index b79796bb87dce3975286f8be2ac54be8e45da7ef..036f50f252b4bfc9cedf5ddeaf1df0f15e84c4ed 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,4 +1,4 @@
-django>=1.10,<1.11
+django>=1.10,<1.12
 
 # Automatically renders Django forms in a pretty, Bootstrap-compatible way.
 django-crispy-forms>=1.5.1