diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 280fb2fc..9d0fff1c 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -14,7 +14,7 @@ jobs:
         export DEBIAN_FRONTEND=noninteractive
         sudo apt-add-repository -y ppa:deadsnakes/ppa
         sudo apt-get -y install python3.7 python3.7-dev python3-pip python3-setuptools
-        sudo python3.7 -m pip install pylint mypy typing-extensions
+        sudo python3.7 -m pip install pylint mypy typing-extensions pytz
     - name: Run checks
       run: make checkfull
         
diff --git a/tools/efrotools/__init__.py b/tools/efrotools/__init__.py
index d4010289..78aa7d4e 100644
--- a/tools/efrotools/__init__.py
+++ b/tools/efrotools/__init__.py
@@ -12,14 +12,6 @@ if TYPE_CHECKING:
     from typing import Dict, Union, Sequence, Optional, Any
 
 
-def get_proc_count() -> int:
-    """Return the number of logical processors available."""
-
-    # Note: this is mac specific currently.
-    return int(
-        subprocess.check_output(['sysctl', '-n', 'hw.ncpu']).decode().strip())
-
-
 def explicit_bool(value: bool) -> bool:
     """Simply return input value; can avoid unreachable-code type warnings."""
     return value
diff --git a/tools/efrotools/code.py b/tools/efrotools/code.py
index f5ee3e91..4c9dce08 100644
--- a/tools/efrotools/code.py
+++ b/tools/efrotools/code.py
@@ -18,7 +18,8 @@ def formatcode(projroot: Path, full: bool) -> None:
     """Run clang-format on all of our source code (multithreaded)."""
     import time
     import concurrent.futures
-    from efrotools import get_files_hash, get_proc_count
+    from efrotools import get_files_hash
+    from multiprocessing import cpu_count
     os.chdir(projroot)
     cachepath = Path(projroot, 'config/.cache-formatcode')
     if full and cachepath.exists():
@@ -50,7 +51,7 @@ def formatcode(projroot: Path, full: bool) -> None:
     # so it actually helps to lighten the load around them.
     # may want to revisit later when we have everything chopped up
     # better
-    with concurrent.futures.ThreadPoolExecutor(max_workers=get_proc_count() //
+    with concurrent.futures.ThreadPoolExecutor(max_workers=cpu_count() //
                                                2) as executor:
         # Converting this to a list will propagate any errors.
         list(executor.map(format_file, dirtyfiles))
@@ -66,7 +67,8 @@ def formatcode(projroot: Path, full: bool) -> None:
 def cpplintcode(projroot: Path, full: bool) -> None:
     """Run lint-checking on all code deemed lint-able."""
     from concurrent.futures import ThreadPoolExecutor
-    from efrotools import get_config, get_proc_count
+    from efrotools import get_config
+    from multiprocessing import cpu_count
     os.chdir(projroot)
     filenames = get_code_filenames(projroot)
     if any(' ' in name for name in filenames):
@@ -98,7 +100,7 @@ def cpplintcode(projroot: Path, full: bool) -> None:
         if result != 0:
             raise Exception(f'Linting failed for {filename}')
 
-    with ThreadPoolExecutor(max_workers=get_proc_count() // 2) as executor:
+    with ThreadPoolExecutor(max_workers=cpu_count() // 2) as executor:
         # Converting this to a list will propagate any errors.
         list(executor.map(lint_file, dirtyfiles))
 
@@ -129,7 +131,8 @@ def formatscripts(projroot: Path, full: bool) -> None:
     """Runs yapf on all our scripts (multithreaded)."""
     import time
     from concurrent.futures import ThreadPoolExecutor
-    from efrotools import get_proc_count, get_files_hash
+    from efrotools import get_files_hash
+    from multiprocessing import cpu_count
     os.chdir(projroot)
     cachepath = Path(projroot, 'config/.cache-formatscripts')
     if full and cachepath.exists():
@@ -158,7 +161,7 @@ def formatscripts(projroot: Path, full: bool) -> None:
     # so it actually helps to lighten the load around them.
     # may want to revisit later when we have everything chopped up
     # better
-    with ThreadPoolExecutor(max_workers=get_proc_count() // 2) as executor:
+    with ThreadPoolExecutor(max_workers=cpu_count() // 2) as executor:
         # Converting this to a list will propagate any errors
         list(executor.map(format_file, dirtyfiles))