diff --git a/net-misc/bird/bird-2.0.10.ebuild b/net-misc/bird/bird-2.0.10.ebuild
index 3f6d411..a69b350 100644
--- a/net-misc/bird/bird-2.0.10.ebuild
+++ b/net-misc/bird/bird-2.0.10.ebuild
@@ -38,7 +38,7 @@ PATCHES=()
 
 src_prepare() {
 	if use elibc_musl; then
-		PATCHES += "${FILESDIR}/${PN}-2.0.9-musl-tests.patch"
+		PATCHES+=("${FILESDIR}/${PN}-2.0.9-musl-tests.patch")
 	fi
 	default
 
diff --git a/net-misc/bird/bird-2.0.11.ebuild b/net-misc/bird/bird-2.0.11.ebuild
index 3f6d411..a69b350 100644
--- a/net-misc/bird/bird-2.0.11.ebuild
+++ b/net-misc/bird/bird-2.0.11.ebuild
@@ -38,7 +38,7 @@ PATCHES=()
 
 src_prepare() {
 	if use elibc_musl; then
-		PATCHES += "${FILESDIR}/${PN}-2.0.9-musl-tests.patch"
+		PATCHES+=("${FILESDIR}/${PN}-2.0.9-musl-tests.patch")
 	fi
 	default
 
diff --git a/net-misc/bird/bird-2.0.9.ebuild b/net-misc/bird/bird-2.0.9.ebuild
index 317c551..13e6b70 100644
--- a/net-misc/bird/bird-2.0.9.ebuild
+++ b/net-misc/bird/bird-2.0.9.ebuild
@@ -38,7 +38,7 @@ PATCHES=()
 
 src_prepare() {
 	if use elibc_musl; then
-		PATCHES += "${FILESDIR}/${P}-musl-tests.patch"
+		PATCHES+=("${FILESDIR}/${P}-musl-tests.patch")
 	fi
 	default