diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index e9a842a466008b4a25e0d40df5ca5c0f16bd774e..3f215a00562f5a74d1d4233c6d7af28807334952 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -16,6 +16,16 @@ Python 3.4:
   - python3.4
   except:
   - tags
+Python 3.4 small integer opt:
+  script:
+  - export PY_EXE=python3.4
+  - curl -L -O -k https://gitlab.tiker.net/inducer/ci-support/raw/master/build-and-test-py-project.sh
+  - ./configure.py --use-imath-sio
+  - ". ./build-and-test-py-project.sh"
+  tags:
+  - python3.4
+  except:
+  - tags
 Python 2.6:
   script:
   - export PY_EXE=python2.6
diff --git a/setup.py b/setup.py
index 730baf11fe920f2246eee1b322c314572b5119bf..b67f0c7c7ae53014c78c68cb3d3da4a9fbc868e6 100644
--- a/setup.py
+++ b/setup.py
@@ -34,7 +34,7 @@ def get_config_schema():
         Switch("USE_SHIPPED_ISL", True, "Use included copy of isl"),
         Switch("USE_SHIPPED_IMATH", True, "Use included copy of imath in isl"),
         Switch("USE_BARVINOK", False, "Include wrapper for Barvinok"),
-        Switch("USE_IMATH_SIO", True, "When using imath, use small-integer "
+        Switch("USE_IMATH_SIO", False, "When using imath, use small-integer "
             "optimization"),
 
         IncludeDir("GMP", []),