diff --git a/lalapps-gcc11-array-bounds-decl.patch b/lalapps-gcc11-array-bounds-decl.patch
new file mode 100644
index 0000000..b37ecfb
--- /dev/null
+++ b/lalapps-gcc11-array-bounds-decl.patch
@@ -0,0 +1,25 @@
+From 929605564d04da773fc4bab553360219077344b9 Mon Sep 17 00:00:00 2001
+From: John Veitch <john.veitch@ligo.org>
+Date: Wed, 12 May 2021 21:53:46 +0100
+Subject: [PATCH] Fix coh_ptf array bounds declaration
+
+---
+ src/ring/coh_PTF_utils.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/src/ring/coh_PTF_utils.c b/src/ring/coh_PTF_utils.c
+index c8a5a96226..0df577c64c 100644
+--- a/src/ring/coh_PTF_utils.c
++++ b/src/ring/coh_PTF_utils.c
+@@ -225,7 +225,7 @@ void coh_PTF_setup_null_stream(
+ /* Be aware this is separate from the null SNR! */
+ int coh_PTF_get_null_stream(
+     struct coh_PTF_params *params,
+-    REAL4TimeSeries **channel,
++    REAL4TimeSeries *channel[LAL_NUM_IFO+1],
+     REAL4 *Fplus,
+     REAL4 *Fcross,
+     REAL4 *timeOffsets )
+-- 
+GitLab
+
diff --git a/lalapps.changes b/lalapps.changes
index be8eec4..3d199cf 100644
--- a/lalapps.changes
+++ b/lalapps.changes
@@ -1,3 +1,11 @@
+-------------------------------------------------------------------
+Tue Jun  8 20:51:27 UTC 2021 - Atri Bhattacharya <badshah400@gmail.com>
+
+- Add lalapps-gcc11-array-bounds-decl.patch: Fix building with gcc
+  11 by correcting array bounds declaration; patch part of
+  upstream merge request
+  [https://git.ligo.org/lscsoft/lalsuite/-/merge_requests/1605].
+
 -------------------------------------------------------------------
 Tue Apr 20 13:53:56 UTC 2021 - Ben Greiner <code@bnavigator.de>
 
diff --git a/lalapps.spec b/lalapps.spec
index e453ba9..3f2edfd 100644
--- a/lalapps.spec
+++ b/lalapps.spec
@@ -29,6 +29,8 @@ URL:            https://wiki.ligo.org/Computing/DASWG/LALSuite
 Source:         http://software.ligo.org/lscsoft/source/lalsuite/%{name}-%{version}.tar.xz
 # PATCH-FIX-UPSTREAM lalapps-fix-uninitialised-var.patch badshah400@gmail.com -- Fix usage of uninitialised variable
 Patch0:         lalapps-fix-uninitialised-var.patch
+# PATCH-FIX-UPSTREAM lalapps-gcc11-array-bounds-decl.patch badshah400@gmail.com -- Fix building with gcc 11 by correcting array bounds declaration; patch part of upstream merge request [https://git.ligo.org/lscsoft/lalsuite/-/merge_requests/1605]
+Patch1:         lalapps-gcc11-array-bounds-decl.patch
 BuildRequires:  %{python_module astropy}
 BuildRequires:  %{python_module devel}
 BuildRequires:  %{python_module glue}