diff --git a/Cargo.lock b/Cargo.lock
index 9dfe88cbe..e0f8c7f6d 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -705,7 +705,7 @@ dependencies = [
  "byteorder 1.2.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand 0.3.22 (registry+https://github.com/rust-lang/crates.io-index)",
- "secp256k1zkp 0.7.1 (git+https://github.com/mimblewimble/rust-secp256k1-zkp?branch=testnet3)",
+ "secp256k1zkp 0.7.1 (git+https://github.com/mimblewimble/rust-secp256k1-zkp?tag=grin_integration_21)",
  "serde 1.0.70 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_derive 1.0.70 (registry+https://github.com/rust-lang/crates.io-index)",
  "slog 2.2.3 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1395,7 +1395,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 [[package]]
 name = "secp256k1zkp"
 version = "0.7.1"
-source = "git+https://github.com/mimblewimble/rust-secp256k1-zkp?branch=testnet3#2564e8cebccb827ed442886d81866af783aaebc4"
+source = "git+https://github.com/mimblewimble/rust-secp256k1-zkp?tag=grin_integration_21#301e6b6b5e19c6738c9d4b6b51e34c5ce256354e"
 dependencies = [
  "arrayvec 0.3.25 (registry+https://github.com/rust-lang/crates.io-index)",
  "gcc 0.3.54 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2076,7 +2076,7 @@ dependencies = [
 "checksum same-file 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)" = "cfb6eded0b06a0b512c8ddbcf04089138c9b4362c2f696f3c3d76039d68f3637"
 "checksum scoped-tls 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "332ffa32bf586782a3efaeb58f127980944bbc8c4d6913a86107ac2a5ab24b28"
 "checksum scopeguard 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)" = "94258f53601af11e6a49f722422f6e3425c52b06245a5cf9bc09908b174f5e27"
-"checksum secp256k1zkp 0.7.1 (git+https://github.com/mimblewimble/rust-secp256k1-zkp?branch=testnet3)" = "<none>"
+"checksum secp256k1zkp 0.7.1 (git+https://github.com/mimblewimble/rust-secp256k1-zkp?tag=grin_integration_21)" = "<none>"
 "checksum semver 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)" = "1d7eb9ef2c18661902cc47e535f9bc51b78acd254da71d375c2f6720d9a40403"
 "checksum semver-parser 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)" = "388a1df253eca08550bef6c72392cfe7c30914bf41df5269b68cbd6ff8f570a3"
 "checksum serde 1.0.70 (registry+https://github.com/rust-lang/crates.io-index)" = "0c3adf19c07af6d186d91dae8927b83b0553d07ca56cbf7f2f32560455c91920"
diff --git a/util/Cargo.toml b/util/Cargo.toml
index ed849f39d..26955c5fd 100644
--- a/util/Cargo.toml
+++ b/util/Cargo.toml
@@ -20,6 +20,6 @@ zip = "0.4"
 
 [dependencies.secp256k1zkp]
 git = "https://github.com/mimblewimble/rust-secp256k1-zkp"
-branch = "testnet3"
+tag = "grin_integration_21"
 #path = "../../rust-secp256k1-zkp"
 features = ["bullet-proof-sizing"]