diff --git a/crates.d/rsp2-array-types.Cargo.toml b/crates.d/rsp2-array-types.Cargo.toml
index fb547ad6..363c7380 100644
--- a/crates.d/rsp2-array-types.Cargo.toml
+++ b/crates.d/rsp2-array-types.Cargo.toml
@@ -17,7 +17,8 @@ path = "lib.rs"
 !!serde { optional = true, features = ["derive"] }
 !!rand
 
-[dev-dependencies]
+# This should be a dev-dependency, but see this bug:
+# https://github.com/rust-lang/cargo/issues/6915
 !!rsp2-assert-close
 
 [features]
diff --git a/crates.d/rsp2-lammps-wrap.Cargo.toml b/crates.d/rsp2-lammps-wrap.Cargo.toml
index 1824d12c..b35d10fc 100644
--- a/crates.d/rsp2-lammps-wrap.Cargo.toml
+++ b/crates.d/rsp2-lammps-wrap.Cargo.toml
@@ -14,6 +14,10 @@ path = "lib.rs"
 !!rsp2-array-types { features = ["serde-support"] }
 !!lammps-sys { features = ["exceptions", "package-user-omp"] }
 
+# This should be a dev-dependency, but see this bug:
+# https://github.com/rust-lang/cargo/issues/6915
+!!rsp2-assert-close
+
 !!log
 !!lazy-static
 !!chrono
@@ -21,9 +25,6 @@ path = "lib.rs"
 !!slice-of-array
 !!mpi { optional = true }
 
-[dev-dependencies]
-!!rsp2-assert-close
-
 [[example]]
 name = "airebo"
 [[example]]
diff --git a/crates.d/rsp2-potentials.Cargo.toml b/crates.d/rsp2-potentials.Cargo.toml
index d94fb8bb..8600b3f2 100644
--- a/crates.d/rsp2-potentials.Cargo.toml
+++ b/crates.d/rsp2-potentials.Cargo.toml
@@ -27,8 +27,11 @@ path = "lib.rs"
 !!rayon-cond
 !!log
 
-[dev-dependencies]
+# This should be a dev-dependency, but see this bug:
+# https://github.com/rust-lang/cargo/issues/6915
 !!rsp2-structure-io
+
+[dev-dependencies]
 !!serde
 !!serde-json
 !!serde-derive
diff --git a/src/io/lammps/Cargo.toml b/src/io/lammps/Cargo.toml
index d71c0a2a..8fd904ed 100644
--- a/src/io/lammps/Cargo.toml
+++ b/src/io/lammps/Cargo.toml
@@ -19,6 +19,10 @@ rsp2-structure = { path = "../../structure", features = ["serde-support"] }
 rsp2-array-types = { path = "../../util/array-types", features = ["serde-support"] }
 lammps-sys = { version = "0.5.2", features = ["exceptions", "package-user-omp"] }
 
+# This should be a dev-dependency, but see this bug:
+# https://github.com/rust-lang/cargo/issues/6915
+rsp2-assert-close = { path = "../../util/assert-close" }
+
 log = "0.4"
 lazy_static = "0.2"
 chrono = "0.4"
@@ -26,9 +30,6 @@ failure = "0.1.2"
 slice-of-array = "0.2.1"
 mpi = { version = "0.5.4", optional = true }
 
-[dev-dependencies]
-rsp2-assert-close = { path = "../../util/assert-close" }
-
 [[example]]
 name = "airebo"
 [[example]]
diff --git a/src/potentials/Cargo.toml b/src/potentials/Cargo.toml
index 3e509e30..7f35155a 100644
--- a/src/potentials/Cargo.toml
+++ b/src/potentials/Cargo.toml
@@ -32,8 +32,11 @@ rayon = "1.0.1"
 rayon-cond = "0.1.0"
 log = "0.4"
 
-[dev-dependencies]
+# This should be a dev-dependency, but see this bug:
+# https://github.com/rust-lang/cargo/issues/6915
 rsp2-structure-io = { path = "../io/structure" }
+
+[dev-dependencies]
 serde = { version = "1.0.91", features = ["rc"] }
 serde_json = "1"
 serde_derive = "1.0.91"
diff --git a/src/util/array-types/Cargo.toml b/src/util/array-types/Cargo.toml
index 2288ca1c..9904aaa0 100644
--- a/src/util/array-types/Cargo.toml
+++ b/src/util/array-types/Cargo.toml
@@ -22,7 +22,8 @@ num-traits = "0.2.3"
 serde = { version = "1.0.91", features = ["derive", "rc"], optional = true }
 rand = "0.3"
 
-[dev-dependencies]
+# This should be a dev-dependency, but see this bug:
+# https://github.com/rust-lang/cargo/issues/6915
 rsp2-assert-close = { path = "../assert-close" }
 
 [features]