diff --git a/intern/opencolorio/ocio_impl_glsl.cc b/intern/opencolorio/ocio_impl_glsl.cc
index e8243a4ae34..e85e5752dda 100644
--- a/intern/opencolorio/ocio_impl_glsl.cc
+++ b/intern/opencolorio/ocio_impl_glsl.cc
@@ -146,6 +146,15 @@ std::list<OCIO_GPUDisplayShader> SHADER_CACHE;
 /** \name Shader
  * \{ */
 
+void string_replace_all(std::string &haystack, const std::string &needle, const std::string &other)
+{
+  size_t i = 0, index;
+  while ((index = haystack.find(needle, i)) != std::string::npos) {
+    haystack.replace(index, needle.size(), other);
+    i = index + other.size();
+  }
+}
+
 static bool createGPUShader(OCIO_GPUShader &shader,
                             OCIO_GPUTextures &textures,
                             const GpuShaderDescRcPtr &shaderdesc_to_scene_linear,
@@ -174,6 +183,17 @@ static bool createGPUShader(OCIO_GPUShader &shader,
     }
   }
 
+  /* Comparison operator in Metal returns per-element comparison and returns a vector of booleans.
+   * Need a special syntax to see if two vec3 are matched.
+   *
+   * NOTE: The replacement is optimized for transforming code  generated by
+   * GradingPrimaryTransform. A more general approach is possible, but for now prefer processing
+   * speed.
+   *
+   * NOTE: The syntax works for all backends Blender supports. */
+  string_replace_all(
+      source, "if ( gamma != vec3(1., 1., 1.) )", "if (! all(equal(gamma, vec3(1., 1., 1.))) )");
+
   StageInterfaceInfo iface("OCIO_Interface", "");
   iface.smooth(Type::VEC2, "texCoord_interp");