diff --git a/requirements.linux.txt b/requirements.linux.txt
index 8fdad02..424cf53 100644
--- a/requirements.linux.txt
+++ b/requirements.linux.txt
@@ -8,7 +8,7 @@ matplotlib==2.0.2
 netCDF4==1.3.0
 numpy==1.13.3
 pandas==0.20.3
-protobuf==3.4.0
+protobuf==3.15.0
 pvlib==0.5.0
 pyparsing==2.2.0
 python-dateutil==2.6.1
diff --git a/requirements.txt b/requirements.txt
index 1de9076..0deaba4 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -8,7 +8,7 @@ matplotlib==2.0.2
 netCDF4==1.3.0
 numpy==1.13.3+mkl
 pandas==0.20.3
-protobuf==3.4.0
+protobuf==3.15.0
 pvlib==0.5.0
 pyparsing==2.2.0
 python-dateutil==2.6.1