diff --git a/src/init.c b/src/init.c
index b8f668d023372..6b55e45ea4733 100644
--- a/src/init.c
+++ b/src/init.c
@@ -698,18 +698,6 @@ void _julia_init(JL_IMAGE_SEARCH rel)
     }
 #endif
 
-#if defined(__linux__)
-    int ncores = jl_cpu_threads();
-    if (ncores > 1) {
-        cpu_set_t cpumask;
-        CPU_ZERO(&cpumask);
-        for(int i=0; i < ncores; i++) {
-            CPU_SET(i, &cpumask);
-        }
-        sched_setaffinity(0, sizeof(cpu_set_t), &cpumask);
-    }
-#endif
-
     if ((jl_options.outputo || jl_options.outputbc) &&
         (jl_options.code_coverage || jl_options.malloc_log)) {
         jl_error("cannot generate code-coverage or track allocation information while generating a .o or .bc output file");
diff --git a/src/julia_internal.h b/src/julia_internal.h
index fc0dd3096a8d9..057081c0e37ad 100644
--- a/src/julia_internal.h
+++ b/src/julia_internal.h
@@ -8,7 +8,6 @@
 #include <uv.h>
 #if !defined(_MSC_VER) && !defined(__MINGW32__)
 #include <unistd.h>
-#include <sched.h>
 #else
 #define sleep(x) Sleep(1000*x)
 #endif
diff --git a/test/threads.jl b/test/threads.jl
index 4f2b3acdc014d..54e11c8df3f19 100644
--- a/test/threads.jl
+++ b/test/threads.jl
@@ -13,3 +13,10 @@ let p, cmd = `$(Base.julia_cmd()) --depwarn=error --startup-file=no threads_exec
         error("threads test failed with nthreads == $other_nthreads")
     end
 end
+
+# issue #34415 - make sure external affinity settings work
+if Sys.islinux() && Sys.CPU_THREADS > 1 && Sys.which("taskset") !== nothing
+    run_with_affinity(spec) = readchomp(`taskset -c $spec $(Base.julia_cmd()) -e "run(\`taskset -p \$(getpid())\`)"`)
+    @test endswith(run_with_affinity("1"), "2")
+    @test endswith(run_with_affinity("0,1"), "3")
+end