diff --git a/base/loading.jl b/base/loading.jl
index 433c7c5521c692..59c7c6b4301374 100644
--- a/base/loading.jl
+++ b/base/loading.jl
@@ -1684,17 +1684,17 @@ function create_expr_cache(pkg::PkgId, input::String, output::String, concrete_d
     deps_eltype = sprint(show, eltype(concrete_deps); context = :module=>nothing)
     deps = deps_eltype * "[" * join(deps_strs, ",") * "]"
     trace = isassigned(PRECOMPILE_TRACE_COMPILE) ? `--trace-compile=$(PRECOMPILE_TRACE_COMPILE[])` : ``
-    io = open(pipeline(`$(julia_cmd()::Cmd) -O0
-                       --output-ji $output --output-incremental=yes
-                       --startup-file=no --history-file=no --warn-overwrite=yes
-                       --color=$(have_color === nothing ? "auto" : have_color ? "yes" : "no")
-                       $trace
-                       -`, stderr = internal_stderr, stdout = internal_stdout),
-              "w", stdout)
+    io = open(pipeline(addenv(`$(julia_cmd()::Cmd) -O0
+                    --output-ji $output --output-incremental=yes
+                    --startup-file=no --history-file=no --warn-overwrite=yes
+                    --color=$(have_color === nothing ? "auto" : have_color ? "yes" : "no")
+                    $trace
+                    -`, "OPENBLAS_NUM_THREADS" => 1), stderr = internal_stderr, stdout = internal_stdout),
+            "w", stdout)
     # write data over stdin to avoid the (unlikely) case of exceeding max command line size
     write(io.in, """
-        Base.include_package_for_output($(pkg_str(pkg)), $(repr(abspath(input))), $(repr(depot_path)), $(repr(dl_load_path)),
-            $(repr(load_path)), $deps, $(repr(source_path(nothing))))
+    Base.include_package_for_output($(pkg_str(pkg)), $(repr(abspath(input))), $(repr(depot_path)), $(repr(dl_load_path)),
+        $(repr(load_path)), $deps, $(repr(source_path(nothing))))
         """)
     close(io.in)
     return io