Remove missing option LIB_PROTO_MUTATOR_WITH_COVERAGE_FLAGS.
diff --git a/CMakeLists.txt b/CMakeLists.txt
index e666eae..ec9510c 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -78,13 +78,11 @@
 endif()
 
 if (SANITIZE_COVERAGE_OPTIONS)
-  if (LIB_PROTO_MUTATOR_WITH_COVERAGE_FLAGS)
-    foreach(OPT ${SANITIZE_COVERAGE_OPTIONS})
-      set(FUZZING_FLAGS "${FUZZING_FLAGS},${OPT}")
-    endforeach()
-    string(SUBSTRING ${FUZZING_FLAGS} 1 -1 FUZZING_FLAGS)
-    set(FUZZING_FLAGS "-fsanitize-coverage=${FUZZING_FLAGS}")
-  endif()
+  foreach(OPT ${SANITIZE_COVERAGE_OPTIONS})
+    set(FUZZING_FLAGS "${FUZZING_FLAGS},${OPT}")
+  endforeach()
+  string(SUBSTRING ${FUZZING_FLAGS} 1 -1 FUZZING_FLAGS)
+  set(FUZZING_FLAGS "-fsanitize-coverage=${FUZZING_FLAGS}")
   set(NO_FUZZING_FLAGS "-fsanitize-coverage=0")
 endif()