diff --git a/artiq/firmware/runtime/Cargo.toml b/artiq/firmware/runtime/Cargo.toml
index 6f4f8b384..01aca8280 100644
--- a/artiq/firmware/runtime/Cargo.toml
+++ b/artiq/firmware/runtime/Cargo.toml
@@ -24,6 +24,7 @@ byteorder = { version = "1.0", default-features = false }
 
 [dependencies.compiler_builtins]
 git = "https://github.com/rust-lang-nursery/compiler-builtins"
+rev = "631b568"
 features = ["mem"]
 
 [dependencies.smoltcp]
diff --git a/conda/artiq-dev/meta.yaml b/conda/artiq-dev/meta.yaml
index 596995a19..f8296788e 100644
--- a/conda/artiq-dev/meta.yaml
+++ b/conda/artiq-dev/meta.yaml
@@ -21,7 +21,7 @@ requirements:
     - llvm-or1k
     - llvmlite-artiq 0.12.0.dev py35_30
     - rust-core-or1k 1.17.0 12
-    - cargo >=0.16.0
+    - cargo =0.11.0
     - openocd >=0.10
     - lit
     - outputcheck