diff --git a/colorspace-fix-assertion-part2.patch b/colorspace-fix-assertion-part2.patch
new file mode 100644
index 0000000..f0c1eda
--- /dev/null
+++ b/colorspace-fix-assertion-part2.patch
@@ -0,0 +1,36 @@
+From bb17c9433bfdc78e296982aad32981bcb9d5514c Mon Sep 17 00:00:00 2001
+From: sekrit-twc <noreply@example.com>
+Date: Tue, 17 Mar 2020 10:40:15 -0700
+Subject: [PATCH] colorspace: fix assertions
+
+---
+ src/zimg/colorspace/operation.cpp | 6 ++++--
+ 1 file changed, 4 insertions(+), 2 deletions(-)
+
+diff --git a/src/zimg/colorspace/operation.cpp b/src/zimg/colorspace/operation.cpp
+index 1218c7b..76f9d7a 100644
+--- a/src/zimg/colorspace/operation.cpp
++++ b/src/zimg/colorspace/operation.cpp
+@@ -65,7 +65,8 @@ std::unique_ptr<Operation> create_lms_to_ictcp_operation(const ColorspaceDefinit
+ std::unique_ptr<Operation> create_gamma_to_linear_operation(const ColorspaceDefinition &in, const ColorspaceDefinition &out, const OperationParams &params, CPUClass cpu)
+ {
+ 	zassert_d(in.primaries == out.primaries, "primaries mismatch");
+-	zassert_d(in.matrix == MatrixCoefficients::RGB && out.matrix == MatrixCoefficients::RGB, "must be RGB");
++	zassert_d((in.matrix == MatrixCoefficients::RGB || in.matrix == MatrixCoefficients::REC_2100_LMS) &&
++	          (out.matrix == MatrixCoefficients::RGB || out.matrix == MatrixCoefficients::REC_2100_LMS), "must be RGB or LMS");
+ 	zassert_d(in.transfer != TransferCharacteristics::LINEAR && out.transfer == TransferCharacteristics::LINEAR, "wrong transfer characteristics");
+ 
+ 	if (in.transfer == TransferCharacteristics::ARIB_B67 && use_display_referred_b67(in.primaries, params))
+@@ -77,7 +78,8 @@ std::unique_ptr<Operation> create_gamma_to_linear_operation(const ColorspaceDefi
+ std::unique_ptr<Operation> create_linear_to_gamma_operation(const ColorspaceDefinition &in, const ColorspaceDefinition &out, const OperationParams &params, CPUClass cpu)
+ {
+ 	zassert_d(in.primaries == out.primaries, "primaries mismatch");
+-	zassert_d(in.matrix == MatrixCoefficients::RGB && out.matrix == MatrixCoefficients::RGB, "must be RGB");
++	zassert_d((in.matrix == MatrixCoefficients::RGB || in.matrix == MatrixCoefficients::REC_2100_LMS) &&
++	          (out.matrix == MatrixCoefficients::RGB || out.matrix == MatrixCoefficients::REC_2100_LMS), "must be RGB or LMS");
+ 	zassert_d(in.transfer == TransferCharacteristics::LINEAR && out.transfer != TransferCharacteristics::LINEAR, "wrong transfer characteristics");
+ 
+ 	if (out.transfer == TransferCharacteristics::ARIB_B67 && use_display_referred_b67(out.primaries, params))
+-- 
+2.25.1
+
diff --git a/zimg.changes b/zimg.changes
index be211c3..1dd59c5 100644
--- a/zimg.changes
+++ b/zimg.changes
@@ -1,3 +1,9 @@
+-------------------------------------------------------------------
+Wed Mar 18 08:15:32 UTC 2020 - Martin Liška <mliska@suse.cz>
+
+- Add colorspace-fix-assertion-part2.patch in order to address
+  gh#sekrit-twc/zimg#123.
+
 -------------------------------------------------------------------
 Tue Mar 17 07:58:45 UTC 2020 - Martin Liška <mliska@suse.cz>
 
diff --git a/zimg.spec b/zimg.spec
index 939ee5a..38a274c 100644
--- a/zimg.spec
+++ b/zimg.spec
@@ -27,7 +27,8 @@ URL:            https://github.com/sekrit-twc/zimg
 Source0:        zimg-%{version}.tar.xz
 Source99:       baselibs.conf
 Patch0:         update-matrix3.cpp.patch
-PAtch1:         colorspace-fix-assertion.patch
+Patch1:         colorspace-fix-assertion.patch
+Patch2:         colorspace-fix-assertion-part2.patch
 BuildRequires:  autoconf
 BuildRequires:  automake
 BuildRequires:  gcc-c++
@@ -59,6 +60,7 @@ developing applications that use libzimg%{sover}.
 %setup -q
 %patch0 -p1
 %patch1 -p1
+%patch2 -p1
 
 %build
 autoreconf -fiv