diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 7c4126c201..bf6fbb65eb 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -9,7 +9,7 @@ on:
 env:
   CARGO_TERM_COLOR: always
   GO_VERSION: '1.21'
-  ACTION_MSRV_TOOLCHAIN: 1.75.0
+  ACTION_MSRV_TOOLCHAIN: 1.66.1
   NIX_VERSION: '2.21.0'
 jobs:
   build:
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 1469713fcd..048789ebe7 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -8,7 +8,7 @@ on:
 env:
   CARGO_TERM_COLOR: always
   GO_VERSION: '1.21'
-  ACTION_MSRV_TOOLCHAIN: 1.75.0
+  ACTION_MSRV_TOOLCHAIN: 1.66.1
 
 jobs:
   build:
diff --git a/Cargo.lock b/Cargo.lock
index 879fb405ce..9a72f8cae0 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -52,9 +52,9 @@ dependencies = [
 
 [[package]]
 name = "anstyle"
-version = "1.0.6"
+version = "1.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8901269c6307e8d93993578286ac0edf7f195079ffff5ebdeea6a59ffb7e36bc"
+checksum = "15c4c2c83f81532e5845a733998b6971faca23490340a418e9b72a3ec9de12ea"
 
 [[package]]
 name = "anstyle-parse"
@@ -284,12 +284,6 @@ version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
 
-[[package]]
-name = "cfg_aliases"
-version = "0.1.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fd16c4719339c4530435d38e511904438d07cce7950afa3718a84ac36c10e89e"
-
 [[package]]
 name = "clap"
 version = "4.3.8"
@@ -348,7 +342,7 @@ version = "0.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7bb11bd1378bf3731b182997b40cefe00aba6a6cc74042c8318c1b271d3badf7"
 dependencies = [
- "nix 0.27.1",
+ "nix",
  "thiserror",
  "tokio",
 ]
@@ -380,7 +374,7 @@ dependencies = [
  "memchr",
  "mockall",
  "multimap",
- "nix 0.28.0",
+ "nix",
  "notify",
  "once_cell",
  "opentelemetry",
@@ -501,15 +495,6 @@ dependencies = [
  "parking_lot_core",
 ]
 
-[[package]]
-name = "deranged"
-version = "0.3.11"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b42b6fa04a440b495c8b04d0e71b707c585f83cb9cb28cf8cd0d976c315e31b4"
-dependencies = [
- "powerfmt",
-]
-
 [[package]]
 name = "digest"
 version = "0.10.7"
@@ -1017,9 +1002,9 @@ checksum = "06d198e9919d9822d5f7083ba8530e04de87841eaf21ead9af8f2304efd57c89"
 
 [[package]]
 name = "itertools"
-version = "0.12.1"
+version = "0.11.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ba291022dbbd398a455acf126c1e341954079855bc60dfdda641363bd6922569"
+checksum = "b1c173a5686ce8bfa551b3563d0c2170bf24ca44da99c7ca4bfdab5418c3fe57"
 dependencies = [
  "either",
 ]
@@ -1101,7 +1086,7 @@ dependencies = [
  "hmac",
  "libc",
  "log",
- "nix 0.27.1",
+ "nix",
  "nom",
  "once_cell",
  "serde",
@@ -1255,19 +1240,6 @@ dependencies = [
  "memoffset",
 ]
 
-[[package]]
-name = "nix"
-version = "0.28.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ab2156c4fce2f8df6c499cc1c763e4394b7482525bf2a9701c9d79d215f519e4"
-dependencies = [
- "bitflags 2.4.1",
- "cfg-if",
- "cfg_aliases",
- "libc",
- "memoffset",
-]
-
 [[package]]
 name = "nom"
 version = "7.1.3"
@@ -1307,12 +1279,6 @@ dependencies = [
  "winapi",
 ]
 
-[[package]]
-name = "num-conv"
-version = "0.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "51d515d32fb182ee37cda2ccdcb92950d6a3c2893aa280e540671c2cd0f3b1d9"
-
 [[package]]
 name = "num-traits"
 version = "0.2.18"
@@ -1508,12 +1474,6 @@ version = "0.3.30"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d231b230927b5e4ad203db57bbcbee2802f6bce620b1e4a9024a07d94e2907ec"
 
-[[package]]
-name = "powerfmt"
-version = "0.2.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "439ee305def115ba05938db6eb1644ff94165c5ab5e9420d1c1bcedbba909391"
-
 [[package]]
 name = "ppv-lite86"
 version = "0.2.17"
@@ -1527,7 +1487,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "059a34f111a9dee2ce1ac2826a68b24601c4298cfeb1a587c3cb493d5ab46f52"
 dependencies = [
  "libc",
- "nix 0.28.0",
+ "nix",
 ]
 
 [[package]]
@@ -1591,9 +1551,9 @@ dependencies = [
 
 [[package]]
 name = "prost"
-version = "0.12.4"
+version = "0.12.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d0f5d036824e4761737860779c906171497f6d55681139d8312388f8fe398922"
+checksum = "146c289cda302b98a28d40c8b3b90498d6e526dd24ac2ecea73e4e491685b94a"
 dependencies = [
  "bytes",
  "prost-derive",
@@ -1601,9 +1561,9 @@ dependencies = [
 
 [[package]]
 name = "prost-derive"
-version = "0.12.4"
+version = "0.12.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "19de2de2a00075bf566bee3bd4db014b11587e84184d3f7a791bc17f1a8e9e48"
+checksum = "efb6c9a1dd1def8e2124d17e83a20af56f1570d6c2d2bd9e266ccb768df3840e"
 dependencies = [
  "anyhow",
  "itertools",
@@ -1989,16 +1949,13 @@ dependencies = [
 
 [[package]]
 name = "time"
-version = "0.3.36"
+version = "0.3.23"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5dfd88e563464686c916c7e46e623e520ddc6d79fa6641390f2e3fa86e83e885"
+checksum = "59e399c068f43a5d116fedaf73b203fa4f9c519f17e2b34f63221d3792f81446"
 dependencies = [
- "deranged",
  "itoa",
  "libc",
- "num-conv",
  "num_threads",
- "powerfmt",
  "serde",
  "time-core",
  "time-macros",
@@ -2006,17 +1963,16 @@ dependencies = [
 
 [[package]]
 name = "time-core"
-version = "0.1.2"
+version = "0.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ef927ca75afb808a4d64dd374f00a2adf8d0fcff8e7b184af886c3c87ec4a3f3"
+checksum = "7300fbefb4dadc1af235a9cef3737cea692a9d97e1b9cbcd4ebdae6f8868e6fb"
 
 [[package]]
 name = "time-macros"
-version = "0.2.18"
+version = "0.2.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3f252a68540fde3a3877aeea552b832b40ab9a69e318efd078774a01ddee1ccf"
+checksum = "96ba15a897f3c86766b757e5ac7221554c6750054d74d5b28844fce5fb36a6c4"
 dependencies = [
- "num-conv",
  "time-core",
 ]
 
diff --git a/conmon-rs/server/Cargo.toml b/conmon-rs/server/Cargo.toml
index 35038db9bb..b385231297 100644
--- a/conmon-rs/server/Cargo.toml
+++ b/conmon-rs/server/Cargo.toml
@@ -21,7 +21,7 @@ libc = "0.2.153"
 libsystemd = "0.7.0"
 memchr = "2.7.2"
 multimap = "0.10.0"
-nix = { version = "0.28.0", features = ["fs", "hostname", "mount", "sched", "signal", "socket", "term", "user"] }
+nix = { version = "=0.27.1", features = ["fs", "hostname", "mount", "sched", "signal", "socket", "term", "user"] }
 notify = "6.1.1"
 once_cell = "1.19.0"
 opentelemetry = "0.22.0"
@@ -53,4 +53,4 @@ dashmap = "5.5.3"
 
 [dev-dependencies]
 mockall = "0.12.1"
-time = { version = "0.3.36", features = ["parsing"] }
+time = { version = "=0.3.23", features = ["parsing"] }