diff --git a/Python/ceval.h b/Python/ceval.h
index bb5f7ddb857246..593fdd853acfbf 100644
--- a/Python/ceval.h
+++ b/Python/ceval.h
@@ -298,7 +298,7 @@ maybe_lltrace_resume_frame(_PyInterpreterFrame *frame, PyObject *globals)
         // Can also be controlled by environment variable
         char *python_lltrace = Py_GETENV("PYTHON_LLTRACE");
         if (python_lltrace != NULL && *python_lltrace >= '0') {
-            lltrace = *python_lltrace - '0';  // TODO: Parse an int and all that
+            lltrace = atoi(python_lltrace);
         }
     }
     if (lltrace >= 5) {
diff --git a/Python/optimizer.c b/Python/optimizer.c
index 5d5aecda4e45e3..98acefceee25ef 100644
--- a/Python/optimizer.c
+++ b/Python/optimizer.c
@@ -625,7 +625,7 @@ _PyJit_translate_single_bytecode_to_trace(
     char *python_lltrace = Py_GETENV("PYTHON_LLTRACE");
     int lltrace = 0;
     if (python_lltrace != NULL && *python_lltrace >= '0') {
-        lltrace = *python_lltrace - '0';  // TODO: Parse an int and all that
+        lltrace = atoi(python_lltrace);
     }
 #endif
     _PyThreadStateImpl *_tstate = (_PyThreadStateImpl *)tstate;
@@ -1033,7 +1033,7 @@ _PyJit_TryInitializeTracing(
     char *python_lltrace = Py_GETENV("PYTHON_LLTRACE");
     int lltrace = 0;
     if (python_lltrace != NULL && *python_lltrace >= '0') {
-        lltrace = *python_lltrace - '0';  // TODO: Parse an int and all that
+        lltrace = atoi(python_lltrace);
     }
     DPRINTF(2,
         "Tracing %s (%s:%d) at byte offset %d at chain depth %d\n",
@@ -1433,7 +1433,7 @@ make_executor_from_uops(_PyThreadStateImpl *tstate, _PyUOpInstruction *buffer, i
     char *python_lltrace = Py_GETENV("PYTHON_LLTRACE");
     int lltrace = 0;
     if (python_lltrace != NULL && *python_lltrace >= '0') {
-        lltrace = *python_lltrace - '0';  // TODO: Parse an int and all that
+        lltrace = atoi(python_lltrace);
     }
     if (lltrace >= 2) {
         printf("Optimized trace (length %d):\n", length);
diff --git a/Python/optimizer_analysis.c b/Python/optimizer_analysis.c
index 095bcfc639bc65..3f2ddfc01b16af 100644
--- a/Python/optimizer_analysis.c
+++ b/Python/optimizer_analysis.c
@@ -47,7 +47,7 @@
         char *uop_debug = Py_GETENV(DEBUG_ENV);
         int lltrace = 0;
         if (uop_debug != NULL && *uop_debug >= '0') {
-            lltrace = *uop_debug - '0';  // TODO: Parse an int and all that
+            lltrace = atoi(uop_debug);
         }
         return lltrace;
     }
diff --git a/Python/optimizer_symbols.c b/Python/optimizer_symbols.c
index 79f81482d247e3..4940395f90d03b 100644
--- a/Python/optimizer_symbols.c
+++ b/Python/optimizer_symbols.c
@@ -65,7 +65,7 @@ static inline int get_lltrace(void) {
     char *uop_debug = Py_GETENV("PYTHON_OPT_DEBUG");
     int lltrace = 0;
     if (uop_debug != NULL && *uop_debug >= '0') {
-        lltrace = *uop_debug - '0';  // TODO: Parse an int and all that
+        lltrace = atoi(uop_debug);
     }
     return lltrace;
 }