diff --git a/Cargo.lock b/Cargo.lock
index 16931e07b..2fc71cdc3 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1052,19 +1052,19 @@ dependencies = [
 
 [[package]]
 name = "proptest"
-version = "1.3.1"
+version = "1.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7c003ac8c77cb07bb74f5f198bce836a689bcd5a42574612bf14d17bfd08c20e"
+checksum = "4e35c06b98bf36aba164cc17cb25f7e232f5c4aeea73baa14b8a9f0d92dbfa65"
 dependencies = [
  "bit-set",
- "bit-vec",
- "bitflags 2.4.1",
+ "bitflags 1.3.2",
+ "byteorder",
  "lazy_static",
  "num-traits",
  "rand",
  "rand_chacha",
  "rand_xorshift",
- "regex-syntax 0.7.5",
+ "regex-syntax 0.6.29",
  "rusty-fork",
  "tempfile",
  "unarray",
@@ -1158,9 +1158,9 @@ dependencies = [
 
 [[package]]
 name = "regex-syntax"
-version = "0.7.5"
+version = "0.6.29"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dbb5fb1acd8a1a18b3dd5be62d25485eb770e05afb408a9627d14d451bae12da"
+checksum = "f162c6dd7b008981e4d40210aca20b4bd0f9b60ca9271061b07f78537722f2e1"
 
 [[package]]
 name = "regex-syntax"
diff --git a/base32ct/Cargo.toml b/base32ct/Cargo.toml
index 2d8e71fd5..c045f6369 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 = "=1.3.1", default-features = false, features = ["std"] }
+proptest = { version = "=1.2.0", default-features = false, features = ["std"] }
 
 [features]
 alloc = []
diff --git a/base64ct/Cargo.toml b/base64ct/Cargo.toml
index a38e7d755..dbb4ef0c5 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 = "=1.3.1", default-features = false, features = ["std"] }
+proptest = { version = "=1.2.0", default-features = false, features = ["std"] }
 
 [features]
 alloc = []