diff --git a/Cargo.lock b/Cargo.lock
index 2fc71cdc3..7086e398b 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1052,19 +1052,19 @@ dependencies = [
 
 [[package]]
 name = "proptest"
-version = "1.2.0"
+version = "1.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4e35c06b98bf36aba164cc17cb25f7e232f5c4aeea73baa14b8a9f0d92dbfa65"
+checksum = "31b476131c3c86cb68032fdc5cb6d5a1045e3e42d96b69fa599fd77701e1f5bf"
 dependencies = [
  "bit-set",
- "bitflags 1.3.2",
- "byteorder",
+ "bit-vec",
+ "bitflags 2.4.1",
  "lazy_static",
  "num-traits",
  "rand",
  "rand_chacha",
  "rand_xorshift",
- "regex-syntax 0.6.29",
+ "regex-syntax",
  "rusty-fork",
  "tempfile",
  "unarray",
@@ -1142,7 +1142,7 @@ dependencies = [
  "aho-corasick",
  "memchr",
  "regex-automata",
- "regex-syntax 0.8.2",
+ "regex-syntax",
 ]
 
 [[package]]
@@ -1153,15 +1153,9 @@ checksum = "5f804c7828047e88b2d32e2d7fe5a105da8ee3264f01902f796c8e067dc2483f"
 dependencies = [
  "aho-corasick",
  "memchr",
- "regex-syntax 0.8.2",
+ "regex-syntax",
 ]
 
-[[package]]
-name = "regex-syntax"
-version = "0.6.29"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f162c6dd7b008981e4d40210aca20b4bd0f9b60ca9271061b07f78537722f2e1"
-
 [[package]]
 name = "regex-syntax"
 version = "0.8.2"
diff --git a/base32ct/Cargo.toml b/base32ct/Cargo.toml
index c045f6369..89e2607bd 100644
--- a/base32ct/Cargo.toml
+++ b/base32ct/Cargo.toml
@@ -19,7 +19,7 @@ rust-version = "1.60"
 [dev-dependencies]
 base32 = "0.4"
 # pinned to preserve MSRV
-proptest = { version = "=1.2.0", default-features = false, features = ["std"] }
+proptest = { version = "=1.4.0", default-features = false, features = ["std"] }
 
 [features]
 alloc = []
diff --git a/base64ct/Cargo.toml b/base64ct/Cargo.toml
index dbb4ef0c5..cab7bd066 100644
--- a/base64ct/Cargo.toml
+++ b/base64ct/Cargo.toml
@@ -19,7 +19,7 @@ rust-version = "1.60"
 [dev-dependencies]
 base64 = "0.21"
 # pinned to preserve MSRV
-proptest = { version = "=1.2.0", default-features = false, features = ["std"] }
+proptest = { version = "=1.4.0", default-features = false, features = ["std"] }
 
 [features]
 alloc = []