diff --git a/Parser/parser.c b/Parser/parser.c
index acfaf80094c..6efaebe179b 100644
--- a/Parser/parser.c
+++ b/Parser/parser.c
@@ -2,10 +2,9 @@
 #include "pegen.h"
 
 #if defined(Py_DEBUG) && defined(Py_BUILD_CORE)
-extern int Py_DebugFlag;
-#define D(x) if (Py_DebugFlag) x;
+#  define D(x) if (Py_DebugFlag) x;
 #else
-#define D(x)
+#  define D(x)
 #endif
 static const int n_keyword_lists = 9;
 static KeywordToken *reserved_keywords[] = {
diff --git a/Tools/peg_generator/pegen/c_generator.py b/Tools/peg_generator/pegen/c_generator.py
index 929ec4f547e..24418ea70e4 100644
--- a/Tools/peg_generator/pegen/c_generator.py
+++ b/Tools/peg_generator/pegen/c_generator.py
@@ -31,10 +31,9 @@ EXTENSION_PREFIX = """\
 #include "pegen.h"
 
 #if defined(Py_DEBUG) && defined(Py_BUILD_CORE)
-extern int Py_DebugFlag;
-#define D(x) if (Py_DebugFlag) x;
+#  define D(x) if (Py_DebugFlag) x;
 #else
-#define D(x)
+#  define D(x)
 #endif
 
 """