diff --git a/Pipfile b/Pipfile
index e0bdd82569f4fe7ff7e57ca232c8f6d8226b0711..0844099bcca4a07323d9d04176f94e80b5415948 100644
--- a/Pipfile
+++ b/Pipfile
@@ -10,8 +10,11 @@ pytest = "*"
 [packages]
 paho-mqtt = "*"
 enum34 = "*"
-PyYAML = "*"
+PyYAML = ">=4.2b1"
 Cerberus = "*"
 
 [requires]
 python_version = "3.6"
+
+[pipenv]
+allow_prereleases = true
diff --git a/Pipfile.lock b/Pipfile.lock
index f29c5bad6a232ce024401e5ffeb6f7d53c97e087..f5745b5561867cd802e0b437e7dfb47549569809 100644
--- a/Pipfile.lock
+++ b/Pipfile.lock
@@ -1,7 +1,7 @@
 {
     "_meta": {
         "hash": {
-            "sha256": "b81a6445bb5ab77c30c665c33801569382b86c4aa9cbda6b5b9cf5be699001cb"
+            "sha256": "d0fca082275026822b30813f6b3a9a34270a6831900af27af77ea4bdfe0ee165"
         },
         "pipfile-spec": 6,
         "requires": {
@@ -42,20 +42,20 @@
         },
         "pyyaml": {
             "hashes": [
-                "sha256:3d7da3009c0f3e783b2c873687652d83b1bbfd5c88e9813fb7e5b03c0dd3108b",
-                "sha256:3ef3092145e9b70e3ddd2c7ad59bdd0252a94dfe3949721633e41344de00a6bf",
-                "sha256:40c71b8e076d0550b2e6380bada1f1cd1017b882f7e16f09a65be98e017f211a",
-                "sha256:558dd60b890ba8fd982e05941927a3911dc409a63dcb8b634feaa0cda69330d3",
-                "sha256:a7c28b45d9f99102fa092bb213aa12e0aaf9a6a1f5e395d36166639c1f96c3a1",
-                "sha256:aa7dd4a6a427aed7df6fb7f08a580d68d9b118d90310374716ae90b710280af1",
-                "sha256:bc558586e6045763782014934bfaf39d48b8ae85a2713117d16c39864085c613",
-                "sha256:d46d7982b62e0729ad0175a9bc7e10a566fc07b224d2c79fafb5e032727eaa04",
-                "sha256:d5eef459e30b09f5a098b9cea68bebfeb268697f78d647bd255a085371ac7f3f",
-                "sha256:e01d3203230e1786cd91ccfdc8f8454c8069c91bee3962ad93b87a4b2860f537",
-                "sha256:e170a9e6fcfd19021dd29845af83bb79236068bf5fd4df3327c1be18182b2531"
+                "sha256:544a0050e76e9b60751c58617fa28c253ad5d23af2e5f0b1c250390bf90bb0df",
+                "sha256:594bf80477a58b6fd53e8b3f24ccf965c25eeeb6e05e4b1fb18c82c2d2090603",
+                "sha256:75e20ca689d0a2bf0c84f0e2028cc68ebef34b213fa66d73c410c53f870c49f4",
+                "sha256:994da68a1dc1050f290f8017f044172360b608c0f2562b47645ecc69d7a61c0a",
+                "sha256:ad902e00088c50bdced94a57b819c24fdadaeaed5494df7a9a67d63774f210fd",
+                "sha256:b11aff75875ffc73541c4e4b1ac2f5e21717c1fc4396238943b9a44d962e74e1",
+                "sha256:bc733b5a9047c3e4848c0e80eeacfa6a799139242606410260c5450d665ea58c",
+                "sha256:d960c68931b96bb215f385baa8ef867b8ebac66af60fa06cc1008f963848c7ad",
+                "sha256:dd461c04e6a91e4eef7d5b75c1fc1c7013d3f8d354033b16526baadddd524079",
+                "sha256:e4d6b5d6218a06f3141189d75c93876dd525a6d15f1b00ef4f274726c93719f1",
+                "sha256:f3c386fa12415bde8a0162745c4badf98fe171c6dfd67e54831f05ec88feeebb"
             ],
             "index": "pypi",
-            "version": "==3.13"
+            "version": "==5.1b5"
         }
     },
     "develop": {
diff --git a/requirements.txt b/requirements.txt
index 60ea772f603199f5aa4c21b52de0d173301a1dc1..e06340d25c12d943ac8bbb5714a32edef716a72a 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,5 +1,5 @@
 paho-mqtt
-PyYAML
+PyYAML>=4.2b1
 enum34
 cerberus