diff --git a/pkgs/build-support/rust/import-cargo-lock.nix b/pkgs/build-support/rust/import-cargo-lock.nix
index 83f4e0df4f2d..3973aff398ab 100644
--- a/pkgs/build-support/rust/import-cargo-lock.nix
+++ b/pkgs/build-support/rust/import-cargo-lock.nix
@@ -12,14 +12,15 @@ let
   # Parse a git source into different components.
   parseGit = src:
     let
-      parts = builtins.match ''git\+([^?]+)(\?rev=(.*))?#(.*)?'' src;
-      rev = builtins.elemAt parts 2;
+      parts = builtins.match ''git\+([^?]+)(\?(rev|tag|branch)=(.*))?#(.*)'' src;
+      type = builtins.elemAt parts 2; # rev, tag or branch
+      value = builtins.elemAt parts 3;
     in
       if parts == null then null
       else {
         url = builtins.elemAt parts 0;
-        sha = builtins.elemAt parts 3;
-      } // lib.optionalAttrs (rev != null) { inherit rev; };
+        sha = builtins.elemAt parts 4;
+      } // lib.optionalAttrs (type != null) { inherit type value; };
 
   packages = (builtins.fromTOML (builtins.readFile lockFile)).package;
 
@@ -137,7 +138,7 @@ let
         cat > $out/.cargo-config <<EOF
         [source."${gitParts.url}"]
         git = "${gitParts.url}"
-        ${lib.optionalString (gitParts ? rev) "rev = \"${gitParts.rev}\""}
+        ${lib.optionalString (gitParts ? type) "${gitParts.type} = \"${gitParts.value}\""}
         replace-with = "vendored-sources"
         EOF
       ''
diff --git a/pkgs/build-support/rust/test/import-cargo-lock/default.nix b/pkgs/build-support/rust/test/import-cargo-lock/default.nix
index 2dd525a8ac3f..95f1711d2da7 100644
--- a/pkgs/build-support/rust/test/import-cargo-lock/default.nix
+++ b/pkgs/build-support/rust/test/import-cargo-lock/default.nix
@@ -1,8 +1,12 @@
 { callPackage }:
 
+# Build like this from nixpkgs root:
+# $ nix-build -A tests.importCargoLock
 {
   basic = callPackage ./basic { };
   gitDependency = callPackage ./git-dependency { };
-  gitDependencyNoRev = callPackage ./git-dependency-no-rev { };
+  gitDependencyRev = callPackage ./git-dependency-rev { };
+  gitDependencyTag = callPackage ./git-dependency-tag { };
+  gitDependencyBranch = callPackage ./git-dependency-branch { };
   maturin = callPackage ./maturin { };
 }
diff --git a/pkgs/build-support/rust/test/import-cargo-lock/git-dependency-branch/Cargo.lock b/pkgs/build-support/rust/test/import-cargo-lock/git-dependency-branch/Cargo.lock
new file mode 100644
index 000000000000..e832b2e5ba4f
--- /dev/null
+++ b/pkgs/build-support/rust/test/import-cargo-lock/git-dependency-branch/Cargo.lock
@@ -0,0 +1,72 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "cfg-if"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
+
+[[package]]
+name = "getrandom"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c9495705279e7140bf035dde1f6e750c162df8b625267cd52cc44e0b156732c8"
+dependencies = [
+ "cfg-if",
+ "libc",
+ "wasi",
+]
+
+[[package]]
+name = "git-dependency-branch"
+version = "0.1.0"
+dependencies = [
+ "rand",
+]
+
+[[package]]
+name = "libc"
+version = "0.2.94"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "18794a8ad5b29321f790b55d93dfba91e125cb1a9edbd4f8e3150acc771c1a5e"
+
+[[package]]
+name = "ppv-lite86"
+version = "0.2.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ac74c624d6b2d21f425f752262f42188365d7b8ff1aff74c82e45136510a4857"
+
+[[package]]
+name = "rand"
+version = "0.8.4"
+source = "git+https://github.com/rust-random/rand.git?branch=master#fcc5baf31565a94f63dce41c2e739e6f182475f4"
+dependencies = [
+ "libc",
+ "rand_chacha",
+ "rand_core",
+]
+
+[[package]]
+name = "rand_chacha"
+version = "0.3.1"
+source = "git+https://github.com/rust-random/rand.git?branch=master#fcc5baf31565a94f63dce41c2e739e6f182475f4"
+dependencies = [
+ "ppv-lite86",
+ "rand_core",
+]
+
+[[package]]
+name = "rand_core"
+version = "0.6.3"
+source = "git+https://github.com/rust-random/rand.git?branch=master#fcc5baf31565a94f63dce41c2e739e6f182475f4"
+dependencies = [
+ "getrandom",
+]
+
+[[package]]
+name = "wasi"
+version = "0.10.2+wasi-snapshot-preview1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fd6fbd9a79829dd1ad0cc20627bf1ed606756a7f77edff7b66b7064f9cb327c6"
diff --git a/pkgs/build-support/rust/test/import-cargo-lock/git-dependency-branch/Cargo.toml b/pkgs/build-support/rust/test/import-cargo-lock/git-dependency-branch/Cargo.toml
new file mode 100644
index 000000000000..0702c5ad8a07
--- /dev/null
+++ b/pkgs/build-support/rust/test/import-cargo-lock/git-dependency-branch/Cargo.toml
@@ -0,0 +1,8 @@
+[package]
+name = "git-dependency-branch"
+version = "0.1.0"
+authors = ["Daniël de Kok <me@danieldk.eu>"]
+edition = "2018"
+
+[dependencies]
+rand = { git = "https://github.com/rust-random/rand.git", branch = "master" }
diff --git a/pkgs/build-support/rust/test/import-cargo-lock/git-dependency-no-rev/default.nix b/pkgs/build-support/rust/test/import-cargo-lock/git-dependency-branch/default.nix
similarity index 60%
rename from pkgs/build-support/rust/test/import-cargo-lock/git-dependency-no-rev/default.nix
rename to pkgs/build-support/rust/test/import-cargo-lock/git-dependency-branch/default.nix
index fc36edc40772..f274d86c52b8 100644
--- a/pkgs/build-support/rust/test/import-cargo-lock/git-dependency-no-rev/default.nix
+++ b/pkgs/build-support/rust/test/import-cargo-lock/git-dependency-branch/default.nix
@@ -1,7 +1,7 @@
 { rustPlatform }:
 
 rustPlatform.buildRustPackage {
-  pname = "git-dependency-no-rev";
+  pname = "git-dependency-branch";
   version = "0.1.0";
 
   src = ./.;
@@ -9,13 +9,13 @@ rustPlatform.buildRustPackage {
   cargoLock = {
     lockFile = ./Cargo.lock;
     outputHashes = {
-      "rand-0.8.3" = "0ya2hia3cn31qa8894s3av2s8j5bjwb6yq92k0jsnlx7jid0jwqa";
+      "rand-0.8.4" = "1ilk9wvfw3mdm57g199ys8f5nrgdrh0n3a4c8b7nz6lgnqvfrv6z";
     };
   };
 
   doInstallCheck = true;
 
   installCheckPhase = ''
-    $out/bin/git-dependency-no-rev
+    $out/bin/git-dependency-branch
   '';
 }
diff --git a/pkgs/build-support/rust/test/import-cargo-lock/git-dependency-no-rev/src/main.rs b/pkgs/build-support/rust/test/import-cargo-lock/git-dependency-branch/src/main.rs
similarity index 100%
rename from pkgs/build-support/rust/test/import-cargo-lock/git-dependency-no-rev/src/main.rs
rename to pkgs/build-support/rust/test/import-cargo-lock/git-dependency-branch/src/main.rs
diff --git a/pkgs/build-support/rust/test/import-cargo-lock/git-dependency-no-rev/Cargo.lock b/pkgs/build-support/rust/test/import-cargo-lock/git-dependency-rev/Cargo.lock
similarity index 76%
rename from pkgs/build-support/rust/test/import-cargo-lock/git-dependency-no-rev/Cargo.lock
rename to pkgs/build-support/rust/test/import-cargo-lock/git-dependency-rev/Cargo.lock
index 54b9c7c5739d..684d9419479d 100644
--- a/pkgs/build-support/rust/test/import-cargo-lock/git-dependency-no-rev/Cargo.lock
+++ b/pkgs/build-support/rust/test/import-cargo-lock/git-dependency-rev/Cargo.lock
@@ -1,5 +1,7 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
+version = 3
+
 [[package]]
 name = "cfg-if"
 version = "1.0.0"
@@ -18,7 +20,7 @@ dependencies = [
 ]
 
 [[package]]
-name = "git-dependency-no-rev"
+name = "git-dependency-rev"
 version = "0.1.0"
 dependencies = [
  "rand",
@@ -39,7 +41,7 @@ checksum = "ac74c624d6b2d21f425f752262f42188365d7b8ff1aff74c82e45136510a4857"
 [[package]]
 name = "rand"
 version = "0.8.3"
-source = "git+https://github.com/rust-random/rand.git#f0e01ee0a7257753cc51b291f62666f4765923ef"
+source = "git+https://github.com/rust-random/rand.git?rev=0.8.3#6ecbe2626b2cc6110a25c97b1702b347574febc7"
 dependencies = [
  "libc",
  "rand_chacha",
@@ -50,7 +52,7 @@ dependencies = [
 [[package]]
 name = "rand_chacha"
 version = "0.3.0"
-source = "git+https://github.com/rust-random/rand.git#f0e01ee0a7257753cc51b291f62666f4765923ef"
+source = "git+https://github.com/rust-random/rand.git?rev=0.8.3#6ecbe2626b2cc6110a25c97b1702b347574febc7"
 dependencies = [
  "ppv-lite86",
  "rand_core",
@@ -58,8 +60,8 @@ dependencies = [
 
 [[package]]
 name = "rand_core"
-version = "0.6.2"
-source = "git+https://github.com/rust-random/rand.git#f0e01ee0a7257753cc51b291f62666f4765923ef"
+version = "0.6.1"
+source = "git+https://github.com/rust-random/rand.git?rev=0.8.3#6ecbe2626b2cc6110a25c97b1702b347574febc7"
 dependencies = [
  "getrandom",
 ]
@@ -67,7 +69,7 @@ dependencies = [
 [[package]]
 name = "rand_hc"
 version = "0.3.0"
-source = "git+https://github.com/rust-random/rand.git#f0e01ee0a7257753cc51b291f62666f4765923ef"
+source = "git+https://github.com/rust-random/rand.git?rev=0.8.3#6ecbe2626b2cc6110a25c97b1702b347574febc7"
 dependencies = [
  "rand_core",
 ]
diff --git a/pkgs/build-support/rust/test/import-cargo-lock/git-dependency-no-rev/Cargo.toml b/pkgs/build-support/rust/test/import-cargo-lock/git-dependency-rev/Cargo.toml
similarity index 51%
rename from pkgs/build-support/rust/test/import-cargo-lock/git-dependency-no-rev/Cargo.toml
rename to pkgs/build-support/rust/test/import-cargo-lock/git-dependency-rev/Cargo.toml
index 770dfb86f523..3500325ae579 100644
--- a/pkgs/build-support/rust/test/import-cargo-lock/git-dependency-no-rev/Cargo.toml
+++ b/pkgs/build-support/rust/test/import-cargo-lock/git-dependency-rev/Cargo.toml
@@ -1,8 +1,8 @@
 [package]
-name = "git-dependency-no-rev"
+name = "git-dependency-rev"
 version = "0.1.0"
 authors = ["Daniël de Kok <me@danieldk.eu>"]
 edition = "2018"
 
 [dependencies]
-rand = { git = "https://github.com/rust-random/rand.git" }
+rand = { git = "https://github.com/rust-random/rand.git", rev = "0.8.3" }
diff --git a/pkgs/build-support/rust/test/import-cargo-lock/git-dependency-rev/default.nix b/pkgs/build-support/rust/test/import-cargo-lock/git-dependency-rev/default.nix
new file mode 100644
index 000000000000..40487d6829a2
--- /dev/null
+++ b/pkgs/build-support/rust/test/import-cargo-lock/git-dependency-rev/default.nix
@@ -0,0 +1,21 @@
+{ rustPlatform }:
+
+rustPlatform.buildRustPackage {
+  pname = "git-dependency-rev";
+  version = "0.1.0";
+
+  src = ./.;
+
+  cargoLock = {
+    lockFile = ./Cargo.lock;
+    outputHashes = {
+      "rand-0.8.3" = "0l3p174bpwia61vcvxz5mw65a13ri3wy94z04xrnyy5lzciykz4f";
+    };
+  };
+
+  doInstallCheck = true;
+
+  installCheckPhase = ''
+    $out/bin/git-dependency-rev
+  '';
+}
diff --git a/pkgs/build-support/rust/test/import-cargo-lock/git-dependency-rev/src/main.rs b/pkgs/build-support/rust/test/import-cargo-lock/git-dependency-rev/src/main.rs
new file mode 100644
index 000000000000..50b4ed799e43
--- /dev/null
+++ b/pkgs/build-support/rust/test/import-cargo-lock/git-dependency-rev/src/main.rs
@@ -0,0 +1,9 @@
+use rand::Rng;
+
+fn main() {
+    let mut rng = rand::thread_rng();
+
+    // Always draw zero :).
+    let roll: u8 = rng.gen_range(0..1);
+    assert_eq!(roll, 0);
+}
diff --git a/pkgs/build-support/rust/test/import-cargo-lock/git-dependency-tag/Cargo.lock b/pkgs/build-support/rust/test/import-cargo-lock/git-dependency-tag/Cargo.lock
new file mode 100644
index 000000000000..9f8ec19a366a
--- /dev/null
+++ b/pkgs/build-support/rust/test/import-cargo-lock/git-dependency-tag/Cargo.lock
@@ -0,0 +1,81 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "cfg-if"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
+
+[[package]]
+name = "getrandom"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c9495705279e7140bf035dde1f6e750c162df8b625267cd52cc44e0b156732c8"
+dependencies = [
+ "cfg-if",
+ "libc",
+ "wasi",
+]
+
+[[package]]
+name = "git-dependency-tag"
+version = "0.1.0"
+dependencies = [
+ "rand",
+]
+
+[[package]]
+name = "libc"
+version = "0.2.94"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "18794a8ad5b29321f790b55d93dfba91e125cb1a9edbd4f8e3150acc771c1a5e"
+
+[[package]]
+name = "ppv-lite86"
+version = "0.2.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ac74c624d6b2d21f425f752262f42188365d7b8ff1aff74c82e45136510a4857"
+
+[[package]]
+name = "rand"
+version = "0.8.3"
+source = "git+https://github.com/rust-random/rand.git?tag=0.8.3#6ecbe2626b2cc6110a25c97b1702b347574febc7"
+dependencies = [
+ "libc",
+ "rand_chacha",
+ "rand_core",
+ "rand_hc",
+]
+
+[[package]]
+name = "rand_chacha"
+version = "0.3.0"
+source = "git+https://github.com/rust-random/rand.git?tag=0.8.3#6ecbe2626b2cc6110a25c97b1702b347574febc7"
+dependencies = [
+ "ppv-lite86",
+ "rand_core",
+]
+
+[[package]]
+name = "rand_core"
+version = "0.6.1"
+source = "git+https://github.com/rust-random/rand.git?tag=0.8.3#6ecbe2626b2cc6110a25c97b1702b347574febc7"
+dependencies = [
+ "getrandom",
+]
+
+[[package]]
+name = "rand_hc"
+version = "0.3.0"
+source = "git+https://github.com/rust-random/rand.git?tag=0.8.3#6ecbe2626b2cc6110a25c97b1702b347574febc7"
+dependencies = [
+ "rand_core",
+]
+
+[[package]]
+name = "wasi"
+version = "0.10.2+wasi-snapshot-preview1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fd6fbd9a79829dd1ad0cc20627bf1ed606756a7f77edff7b66b7064f9cb327c6"
diff --git a/pkgs/build-support/rust/test/import-cargo-lock/git-dependency-tag/Cargo.toml b/pkgs/build-support/rust/test/import-cargo-lock/git-dependency-tag/Cargo.toml
new file mode 100644
index 000000000000..1bda7336c263
--- /dev/null
+++ b/pkgs/build-support/rust/test/import-cargo-lock/git-dependency-tag/Cargo.toml
@@ -0,0 +1,8 @@
+[package]
+name = "git-dependency-tag"
+version = "0.1.0"
+authors = ["Daniël de Kok <me@danieldk.eu>"]
+edition = "2018"
+
+[dependencies]
+rand = { git = "https://github.com/rust-random/rand.git", tag = "0.8.3" }
diff --git a/pkgs/build-support/rust/test/import-cargo-lock/git-dependency-tag/default.nix b/pkgs/build-support/rust/test/import-cargo-lock/git-dependency-tag/default.nix
new file mode 100644
index 000000000000..2a2f860ac8a1
--- /dev/null
+++ b/pkgs/build-support/rust/test/import-cargo-lock/git-dependency-tag/default.nix
@@ -0,0 +1,21 @@
+{ rustPlatform }:
+
+rustPlatform.buildRustPackage {
+  pname = "git-dependency-tag";
+  version = "0.1.0";
+
+  src = ./.;
+
+  cargoLock = {
+    lockFile = ./Cargo.lock;
+    outputHashes = {
+      "rand-0.8.3" = "0l3p174bpwia61vcvxz5mw65a13ri3wy94z04xrnyy5lzciykz4f";
+    };
+  };
+
+  doInstallCheck = true;
+
+  installCheckPhase = ''
+    $out/bin/git-dependency-tag
+  '';
+}
diff --git a/pkgs/build-support/rust/test/import-cargo-lock/git-dependency-tag/src/main.rs b/pkgs/build-support/rust/test/import-cargo-lock/git-dependency-tag/src/main.rs
new file mode 100644
index 000000000000..50b4ed799e43
--- /dev/null
+++ b/pkgs/build-support/rust/test/import-cargo-lock/git-dependency-tag/src/main.rs
@@ -0,0 +1,9 @@
+use rand::Rng;
+
+fn main() {
+    let mut rng = rand::thread_rng();
+
+    // Always draw zero :).
+    let roll: u8 = rng.gen_range(0..1);
+    assert_eq!(roll, 0);
+}
diff --git a/pkgs/build-support/rust/test/import-cargo-lock/git-dependency/Cargo.lock b/pkgs/build-support/rust/test/import-cargo-lock/git-dependency/Cargo.lock
index 50600ef4caa5..fa71865b3e5f 100644
--- a/pkgs/build-support/rust/test/import-cargo-lock/git-dependency/Cargo.lock
+++ b/pkgs/build-support/rust/test/import-cargo-lock/git-dependency/Cargo.lock
@@ -1,5 +1,7 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
+version = 3
+
 [[package]]
 name = "cfg-if"
 version = "1.0.0"
@@ -39,7 +41,7 @@ checksum = "ac74c624d6b2d21f425f752262f42188365d7b8ff1aff74c82e45136510a4857"
 [[package]]
 name = "rand"
 version = "0.8.3"
-source = "git+https://github.com/rust-random/rand.git?rev=0.8.3#6ecbe2626b2cc6110a25c97b1702b347574febc7"
+source = "git+https://github.com/rust-random/rand.git#f0e01ee0a7257753cc51b291f62666f4765923ef"
 dependencies = [
  "libc",
  "rand_chacha",
@@ -50,7 +52,7 @@ dependencies = [
 [[package]]
 name = "rand_chacha"
 version = "0.3.0"
-source = "git+https://github.com/rust-random/rand.git?rev=0.8.3#6ecbe2626b2cc6110a25c97b1702b347574febc7"
+source = "git+https://github.com/rust-random/rand.git#f0e01ee0a7257753cc51b291f62666f4765923ef"
 dependencies = [
  "ppv-lite86",
  "rand_core",
@@ -58,8 +60,8 @@ dependencies = [
 
 [[package]]
 name = "rand_core"
-version = "0.6.1"
-source = "git+https://github.com/rust-random/rand.git?rev=0.8.3#6ecbe2626b2cc6110a25c97b1702b347574febc7"
+version = "0.6.2"
+source = "git+https://github.com/rust-random/rand.git#f0e01ee0a7257753cc51b291f62666f4765923ef"
 dependencies = [
  "getrandom",
 ]
@@ -67,7 +69,7 @@ dependencies = [
 [[package]]
 name = "rand_hc"
 version = "0.3.0"
-source = "git+https://github.com/rust-random/rand.git?rev=0.8.3#6ecbe2626b2cc6110a25c97b1702b347574febc7"
+source = "git+https://github.com/rust-random/rand.git#f0e01ee0a7257753cc51b291f62666f4765923ef"
 dependencies = [
  "rand_core",
 ]
diff --git a/pkgs/build-support/rust/test/import-cargo-lock/git-dependency/Cargo.toml b/pkgs/build-support/rust/test/import-cargo-lock/git-dependency/Cargo.toml
index 11ee8b1763e6..a902dea9fcd0 100644
--- a/pkgs/build-support/rust/test/import-cargo-lock/git-dependency/Cargo.toml
+++ b/pkgs/build-support/rust/test/import-cargo-lock/git-dependency/Cargo.toml
@@ -5,4 +5,4 @@ authors = ["Daniël de Kok <me@danieldk.eu>"]
 edition = "2018"
 
 [dependencies]
-rand = { git = "https://github.com/rust-random/rand.git", rev = "0.8.3" }
+rand = { git = "https://github.com/rust-random/rand.git" }
diff --git a/pkgs/build-support/rust/test/import-cargo-lock/git-dependency/default.nix b/pkgs/build-support/rust/test/import-cargo-lock/git-dependency/default.nix
index 17276c5f5c3c..944de9b45cb5 100644
--- a/pkgs/build-support/rust/test/import-cargo-lock/git-dependency/default.nix
+++ b/pkgs/build-support/rust/test/import-cargo-lock/git-dependency/default.nix
@@ -9,7 +9,7 @@ rustPlatform.buildRustPackage {
   cargoLock = {
     lockFile = ./Cargo.lock;
     outputHashes = {
-      "rand-0.8.3" = "0l3p174bpwia61vcvxz5mw65a13ri3wy94z04xrnyy5lzciykz4f";
+      "rand-0.8.3" = "0ya2hia3cn31qa8894s3av2s8j5bjwb6yq92k0jsnlx7jid0jwqa";
     };
   };