diff --git a/ir_measures/measures/accuracy.py b/ir_measures/measures/accuracy.py
index fa8c410..fae8b5e 100644
--- a/ir_measures/measures/accuracy.py
+++ b/ir_measures/measures/accuracy.py
@@ -1,5 +1,5 @@
 from ir_measures import measures
-from .base import Measure, ParamInfo
+from ir_measures.measures.base import Measure, ParamInfo
 
 class _Accuracy(Measure):
     """
diff --git a/ir_measures/measures/numq.py b/ir_measures/measures/numq.py
index ce2f701..05f3143 100644
--- a/ir_measures/measures/numq.py
+++ b/ir_measures/measures/numq.py
@@ -1,5 +1,5 @@
 from ir_measures import measures
-from .base import SumAgg
+from ir_measures.measures.base import SumAgg
 
 
 class _NumQ(measures.Measure):
diff --git a/ir_measures/measures/numrel.py b/ir_measures/measures/numrel.py
index 16e21aa..e32bf28 100644
--- a/ir_measures/measures/numrel.py
+++ b/ir_measures/measures/numrel.py
@@ -1,5 +1,5 @@
 from ir_measures import measures
-from .base import SumAgg
+from ir_measures.measures.base import SumAgg
 
 
 class _NumRel(measures.Measure):
diff --git a/ir_measures/measures/numret.py b/ir_measures/measures/numret.py
index ef316ed..59549a4 100644
--- a/ir_measures/measures/numret.py
+++ b/ir_measures/measures/numret.py
@@ -1,5 +1,5 @@
 from ir_measures import measures
-from .base import SumAgg
+from ir_measures.measures.base import SumAgg
 
 
 class _NumRet(measures.Measure):