diff --git a/requirements-cpu.txt b/requirements-cpu.txt
index 52177a6..af8677f 100644
--- a/requirements-cpu.txt
+++ b/requirements-cpu.txt
@@ -1,3 +1,4 @@
+numpy==1.15.4
 pathlib==1.0.1
 scandir==1.6
 h5py==2.7.1
diff --git a/requirements-gpu-cuda9-cudnn7.txt b/requirements-gpu-cuda9-cudnn7.txt
index 17a265f..54df6b8 100644
--- a/requirements-gpu-cuda9-cudnn7.txt
+++ b/requirements-gpu-cuda9-cudnn7.txt
@@ -1,3 +1,4 @@
+numpy==1.15.4
 pathlib==1.0.1
 scandir==1.6
 h5py==2.7.1