diff --git a/setup.py b/setup.py
index afd73e4a..298da7dd 100644
--- a/setup.py
+++ b/setup.py
@@ -28,15 +28,17 @@ if sys.version_info >= (3, 0):
     requirements.append("halo")
     requirements.append("networkx")
     requirements.append("vivisect==1.0.0")
-    requirements.append("viv-utils==0.3.19")
+    requirements.append("viv-utils[flirt]==0.4.1")
     requirements.append("smda==1.5.13")
-    requirements.append("python-flirt~=0.5.4")
 else:
     # py2
     requirements.append("enum34==1.1.6")  # v1.1.6 is needed by halo 0.0.30 / spinners 0.0.24
     requirements.append("halo==0.0.30")  # halo==0.0.30 is the last version to support py2.7
     requirements.append("vivisect==0.1.0")
-    requirements.append("viv-utils==0.3.19")
+    # TODO: issue here with flirt not being supported.
+    # but we're also no longer supporting py2
+    # so this whole block goes away.
+    requirements.append("viv-utils==0.4.1")
     requirements.append("networkx==2.2")  # v2.2 is last version supported by Python 2.7
     requirements.append("backports.functools-lru-cache")