--- a/dom/canvas/WebGLShaderValidator.cpp
+++ b/dom/canvas/WebGLShaderValidator.cpp
@@ -48,16 +48,21 @@ ChooseValidatorCompileOptions(const ShBu
 #ifdef XP_MACOSX
         // Work around https://bugs.webkit.org/show_bug.cgi?id=124684,
         // https://chromium.googlesource.com/angle/angle/+/5e70cf9d0b1bb
         options |= SH_UNFOLD_SHORT_CIRCUIT;
 
         // Work around that Mac drivers handle struct scopes incorrectly.
         options |= SH_REGENERATE_STRUCT_NAMES;
         options |= SH_INIT_OUTPUT_VARIABLES;
+
+        // Work around that Intel drivers on Mac OSX handle for-loop incorrectly.
+        if (gl->Vendor() == gl::GLVendor::Intel) {
+            options |= SH_ADD_AND_TRUE_TO_LOOP_CONDITION;
+        }
 #endif
 
         if (!gl->IsANGLE() && gl->Vendor() == gl::GLVendor::Intel) {
             // Failures on at least Windows+Intel+OGL on:
             // conformance/glsl/constructors/glsl-construct-mat2.html
             options |= SH_SCALARIZE_VEC_AND_MAT_CONSTRUCTOR_ARGS;
         }
     }