diff --git a/scripts/generate_keys.py b/scripts/generate_keys.py
index 5da4388..57d6b1d 100755
--- a/scripts/generate_keys.py
+++ b/scripts/generate_keys.py
@@ -9,9 +9,12 @@
 try:
     import monocypher
 except ImportError:
-    print("Please install monocypher with: python3 -m pip install pymonocypher")
+    Logs.error("Please install monocypher with: python3 -m pip install pymonocypher==3.1.3.2")
     sys.exit(1)
 
+if monocypher.__version__ != "3.1.3.2":
+    Logs.error("must use monocypher 3.1.3.2, please run: python3 -m pip install pymonocypher==3.1.3.2")
+    sys.exit(1)
 
 if len(sys.argv) != 2:
     print("Usage: generate_keys.py BASENAME")
diff --git a/scripts/install_build_env.sh b/scripts/install_build_env.sh
index cdf2b5d..b7482ae 100755
--- a/scripts/install_build_env.sh
+++ b/scripts/install_build_env.sh
@@ -5,7 +5,7 @@ python3 -m pip install pymavlink
 python3 -m pip install dronecan
 python3 -m pip install pyserial
 python3 -m pip install pexpect
-python3 -m pip install pymonocypher
+python3 -m pip install pymonocypher==3.1.3.2
 
 wget https://downloads.arduino.cc/arduino-cli/arduino-cli_0.27.1_Linux_64bit.tar.gz
 mkdir -p bin
diff --git a/scripts/secure_command.py b/scripts/secure_command.py
index 7d87f5f..1ead22b 100755
--- a/scripts/secure_command.py
+++ b/scripts/secure_command.py
@@ -10,7 +10,7 @@
 try:
     import monocypher
 except ImportError:
-    print("Please install monocypher with: python3 -m pip install pymonocypher")
+    print("Please install monocypher with: python3 -m pip install pymonocypher==3.1.3.2")
     sys.exit(1)
 
 
diff --git a/scripts/sign_fw.py b/scripts/sign_fw.py
index 41d5d98..f11c507 100755
--- a/scripts/sign_fw.py
+++ b/scripts/sign_fw.py
@@ -10,7 +10,7 @@
 try:
     import monocypher
 except ImportError:
-    print("Please install monocypher with: python3 -m pip install pymonocypher")
+    print("Please install monocypher with: python3 -m pip install pymonocypher==3.1.3.2")
     sys.exit(1)
 
 key_len = 32