diff --git a/pkgs/development/compilers/rust/rustc.nix b/pkgs/development/compilers/rust/rustc.nix
index ce0dcf1613bf..bd883d1bea86 100644
--- a/pkgs/development/compilers/rust/rustc.nix
+++ b/pkgs/development/compilers/rust/rustc.nix
@@ -136,6 +136,10 @@ in stdenv.mkDerivation rec {
 
     # Useful debugging parameter
     # export VERBOSE=1
+  '' + lib.optionalString (stdenv.isDarwin && stdenv.isx86_64) ''
+    # See https://github.com/jemalloc/jemalloc/issues/1997
+    # Using a value of 48 should work on both emulated and native x86_64-darwin.
+    export JEMALLOC_SYS_WITH_LG_VADDR=48
   '';
 
   # rustc unfortunately needs cmake to compile llvm-rt but doesn't