diff --git a/CMake/unix-cache.cmake b/CMake/unix-cache.cmake
index 2c85626a49..a0369e84e5 100644
--- a/CMake/unix-cache.cmake
+++ b/CMake/unix-cache.cmake
@@ -142,7 +142,7 @@ set(HAVE_GETRLIMIT 1)
 set(HAVE_GETSOCKNAME 1)
 set(HAVE_GETTIMEOFDAY 1)
 if(CMAKE_SYSTEM_NAME STREQUAL "Linux")
-  set(HAVE_GLIBC_STRERROR_R 1)
+  # Depends on C library.
 else()
   set(HAVE_GLIBC_STRERROR_R 0)
 endif()
@@ -164,7 +164,7 @@ else()
 endif()
 set(HAVE_LIBGEN_H 1)
 if(CMAKE_SYSTEM_NAME STREQUAL "Linux")
-  set(HAVE_LINUX_TCP_H 1)
+  # Requires Linux kernel userspace headers. Expected with glibc. May be missing by default with MUSL.
 else()
   set(HAVE_LINUX_TCP_H 0)
 endif()