diff --git a/Cargo.toml b/Cargo.toml
index e941b46..e45c9e8 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -22,21 +22,24 @@ structopt = "0.2"
 pest = "2.0"
 pest_derive = "2.0"
 failure = "0.1"
-rand = "0.5"
+rand = "0.6"
 data-encoding = "2.1"
 regex-syntax = "0.6"
 pbr = "1.0"
 num-traits = "0.2"
 rayon = "1.0"
-zipf = "4.0.1"
+zipf = "5.0"
 chrono = { version = "0.4", default-features = false }
 ryu = "0.2"
-pcg_rand = "0.9.3"
-xoshiro = "0.0.4"
 serde_derive = "1.0"
 serde = "1.0"
 muldiv = "0.2"
-rand_regex = "0.11"
+rand_regex = "0.12"
+rand_pcg = "0.1"
+rand_isaac = "0.1"
+rand_chacha = "0.1"
+rand_hc = "0.1"
+rand_xorshift = "0.1"
 
 [dev-dependencies]
 regex = "1.0"
diff --git a/src/cli.rs b/src/cli.rs
index b837866..d959fd3 100644
--- a/src/cli.rs
+++ b/src/cli.rs
@@ -1,15 +1,5 @@
 //! CLI driver of `dbgen`.
 
-// TODO remove these `extern crate` once racer-rust/racer#916 is closed.
-extern crate data_encoding;
-extern crate failure;
-extern crate pbr;
-extern crate pcg_rand;
-extern crate rand;
-extern crate rayon;
-extern crate structopt;
-extern crate xoshiro;
-
 use crate::{
     eval::{Row, State},
     format::{Format, SqlFormat},
@@ -20,7 +10,10 @@ use data_encoding::{DecodeError, DecodeKind, HEXLOWER_PERMISSIVE};
 use failure::{Error, Fail, ResultExt};
 use muldiv::MulDiv;
 use pbr::{MultiBar, Units};
-use rand::{prng, EntropyRng, Rng, RngCore, SeedableRng, StdRng};
+use rand::{
+    rngs::{EntropyRng, StdRng},
+    Rng, RngCore, SeedableRng,
+};
 use rayon::{
     iter::{IntoParallelIterator, ParallelIterator},
     ThreadPoolBuilder,
@@ -270,10 +263,8 @@ pub enum RngName {
     Isaac64,
     /// Xorshift
     XorShift,
-    /// PCG32-Oneseq
+    /// PCG32
     Pcg32,
-    /// xoshiro256**
-    Xoshiro256StarStar,
 }
 
 impl FromStr for RngName {
@@ -286,7 +277,6 @@ impl FromStr for RngName {
             "isaac64" => RngName::Isaac64,
             "xorshift" => RngName::XorShift,
             "pcg32" => RngName::Pcg32,
-            "xoshiro256**" => RngName::Xoshiro256StarStar,
             _ => failure::bail!("Unsupported RNG {}", name),
         })
     }
@@ -295,17 +285,13 @@ impl FromStr for RngName {
 impl RngName {
     /// Creates an RNG engine given the name. The RNG engine instance will be seeded from `src`.
     fn create(self, src: &mut StdRng) -> Box<dyn RngCore + Send> {
-        use pcg_rand::{seeds::PcgSeeder, Pcg32Oneseq};
-        use xoshiro::Xoshiro256StarStar;
-
         match self {
-            RngName::ChaCha => Box::new(prng::ChaChaRng::from_seed(src.gen())),
-            RngName::Hc128 => Box::new(prng::Hc128Rng::from_seed(src.gen())),
-            RngName::Isaac => Box::new(prng::IsaacRng::from_seed(src.gen())),
-            RngName::Isaac64 => Box::new(prng::Isaac64Rng::from_seed(src.gen())),
-            RngName::XorShift => Box::new(prng::XorShiftRng::from_seed(src.gen())),
-            RngName::Pcg32 => Box::new(Pcg32Oneseq::from_seed(PcgSeeder::seed(src.gen()))),
-            RngName::Xoshiro256StarStar => Box::new(Xoshiro256StarStar::from_seed(src.gen())),
+            RngName::ChaCha => Box::new(rand_chacha::ChaChaRng::from_seed(src.gen())),
+            RngName::Hc128 => Box::new(rand_hc::Hc128Rng::from_seed(src.gen())),
+            RngName::Isaac => Box::new(rand_isaac::IsaacRng::from_seed(src.gen())),
+            RngName::Isaac64 => Box::new(rand_isaac::Isaac64Rng::from_seed(src.gen())),
+            RngName::XorShift => Box::new(rand_xorshift::XorShiftRng::from_seed(src.gen())),
+            RngName::Pcg32 => Box::new(rand_pcg::Pcg32::from_seed(src.gen())),
         }
     }
 }
diff --git a/src/eval.rs b/src/eval.rs
index b77854e..3512de8 100644
--- a/src/eval.rs
+++ b/src/eval.rs
@@ -333,15 +333,15 @@ pub fn compile_function(name: Function, args: &[impl AsValue]) -> Result<Compile
         }
 
         Function::RandUniform => {
-            let lower = arg(name, args, 0, None)?;
-            let upper = arg(name, args, 1, None)?;
+            let lower = arg::<f64, _>(name, args, 0, None)?;
+            let upper = arg::<f64, _>(name, args, 1, None)?;
             require!(lower < upper, "{} < {}", lower, upper);
             Ok(Compiled(C::RandUniformF64(Uniform::new(lower, upper))))
         }
 
         Function::RandUniformInclusive => {
-            let lower = arg(name, args, 0, None)?;
-            let upper = arg(name, args, 1, None)?;
+            let lower = arg::<f64, _>(name, args, 0, None)?;
+            let upper = arg::<f64, _>(name, args, 1, None)?;
             require!(lower <= upper, "{} <= {}", lower, upper);
             Ok(Compiled(C::RandUniformF64(Uniform::new_inclusive(lower, upper))))
         }
diff --git a/src/lib.rs b/src/lib.rs
index 928c6aa..98b7491 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -11,23 +11,10 @@
         rust_2018_idioms
     )
 )]
-#![cfg_attr(feature = "cargo-clippy", allow(clippy::stutter, unused_extern_crates))]
+#![cfg_attr(feature = "cargo-clippy", allow(clippy::stutter))]
 
 //! The reusable library powering `dbgen`.
 
-// TODO remove these `extern crate` once racer-rust/racer#916 is closed.
-extern crate chrono;
-extern crate data_encoding;
-extern crate failure;
-extern crate num_traits;
-extern crate pest;
-extern crate rand;
-extern crate rand_regex;
-extern crate regex_syntax;
-extern crate ryu;
-extern crate structopt;
-extern crate zipf;
-
 pub mod cli;
 pub mod error;
 pub mod eval;