diff --git a/Makefile b/Makefile
index 7b64106930..73edfa7824 100644
--- a/Makefile
+++ b/Makefile
@@ -1198,6 +1198,7 @@ endif
 # Set CFLAGS, LDFLAGS and other *FLAGS variables. These might be
 # tweaked by config.* below as well as the command-line, both of
 # which'll override these defaults.
+# Older versions of GCC may require adding "-std=gnu99" at the end.
 CFLAGS = -g -O2 -Wall
 LDFLAGS =
 CC_LD_DYNPATH = -Wl,-rpath,
diff --git a/revision.c b/revision.c
index 9dff845bed..253a159e69 100644
--- a/revision.c
+++ b/revision.c
@@ -43,10 +43,15 @@ static inline int want_ancestry(const struct rev_info *revs);
 
 void show_object_with_name(FILE *out, struct object *obj, const char *name)
 {
-	const char *p;
-
 	fprintf(out, "%s ", oid_to_hex(&obj->oid));
-	for (p = name; *p && *p != '\n'; p++)
+	/*
+	 * This "for (const char *p = ..." is made as a first step towards
+	 * making use of such declarations elsewhere in our codebase.  If
+	 * it causes compilation problems on your platform, please report
+	 * it to the Git mailing list at git@vger.kernel.org. In the meantime,
+	 * adding -std=gnu99 to CFLAGS may help if you are with older GCC.
+	 */
+	for (const char *p = name; *p && *p != '\n'; p++)
 		fputc(*p, out);
 	fputc('\n', out);
 }