diff --git a/quota-4.06-Drop-sys-cdefs.h-usage.patch b/quota-4.06-Drop-sys-cdefs.h-usage.patch
new file mode 100644
index 0000000..c11741c
--- /dev/null
+++ b/quota-4.06-Drop-sys-cdefs.h-usage.patch
@@ -0,0 +1,43 @@
+From 1959f3768a284315250acd4d17a9f5ef0b8ea189 Mon Sep 17 00:00:00 2001
+From: Jan Kara <jack@suse.cz>
+Date: Mon, 30 Nov 2020 16:35:26 +0100
+Subject: [PATCH] Drop sys/cdefs.h usage
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+quota.h header includes sys/cdefs.h because it uses __P() macro in
+quotactl syscall declaration. However glibc currently defines __P() is
+nop and it only causes issues with other libc implementations (e.g. musl
+libc). So just drop __P() usage and sys/cdefs.h include.
+
+Reported-by: 2xsaiko <git@dblsaiko.net>
+Signed-off-by: Jan Kara <jack@suse.cz>
+Signed-off-by: Petr Písař <ppisar@redhat.com>
+---
+ quota.h | 3 +--
+ 1 file changed, 1 insertion(+), 2 deletions(-)
+
+diff --git a/quota.h b/quota.h
+index 4c21411..845cbbd 100644
+--- a/quota.h
++++ b/quota.h
+@@ -1,7 +1,6 @@
+ #ifndef GUARD_QUOTA_H
+ #define GUARD_QUOTA_H
+ 
+-#include <sys/cdefs.h>
+ #include <sys/types.h>
+ #include <stdint.h>
+ 
+@@ -182,6 +181,6 @@ enum {
+ 	#endif
+ #endif
+ 
+-long quotactl __P((int, const char *, qid_t, caddr_t));
++long quotactl(int, const char *, qid_t, caddr_t);
+ 
+ #endif /* _QUOTA_ */
+-- 
+2.26.2
+
diff --git a/quota.spec b/quota.spec
index 537a9ab..c6c1189 100644
--- a/quota.spec
+++ b/quota.spec
@@ -67,6 +67,8 @@ Patch3:     quota-4.06-quotaops-fix-compilation-warning.patch
 # Warn when kernel XFS large time stamp does fit into (32-bit) user-space
 # time_t, in upstream after 4.06
 Patch4:     quota-4.06-quotaio_xfs-Warn-when-large-kernel-timestamps-cannot.patch
+# Do not use a pointless compiler-internal __P() macro, in upstream after 4.06
+Patch5:     quota-4.06-Drop-sys-cdefs.h-usage.patch
 BuildRequires:  autoconf
 BuildRequires:  automake
 BuildRequires:  bash
@@ -192,6 +194,7 @@ Linux/UNIX environment.
 %patch2 -p1
 %patch3 -p1
 %patch4 -p1
+%patch5 -p1
 # Regenerate build scripts
 autoreconf -f -i
 
@@ -346,6 +349,7 @@ make check
 - Fix a compilation warning in quotaops.c
 - Warn when kernel XFS large time stamp does fit into (32-bit) user-space
   time_t
+- Do not use a pointless compiler-internal __P() macro
 
 * Tue Nov 10 2020 Petr Pisar <ppisar@redhat.com> - 1:4.06-1
 - 4.06 bump