diff --git a/Build.md b/Build.md
index 0ef098e..52c247b 100644
--- a/Build.md
+++ b/Build.md
@@ -1,7 +1,7 @@
-* CMake 3.1 or higher
+* CMake 3.8 or higher
 * C++ Compiler with C++17 support:
   * Clang 5 or higher
-  * GCC 7 or higher (`optional,string_view` require libstdc++7 or higher)
+  * GCC 7.3 or higher (`optional,string_view` require libstdc++7 or higher)
   * MSVC 2017 or higher (included with VS2017 Build Tools)
 
 See [[Getting-started]] for recommended configuration options for common systems.
diff --git a/Getting-started.md b/Getting-started.md
index e25d98b..62b2c56 100644
--- a/Getting-started.md
+++ b/Getting-started.md
@@ -6,7 +6,8 @@
 
 ### Build the ccls language server
 
-* On Linux, building requires libstdc++ shipped with GCC > 7.0 for C++17 header files, even if you use clang++.
+* cmake >= 3.8 for C++17 support
+* On Linux, building requires libstdc++ shipped with GCC >= 7.3 for C++17 header files, even if you use clang++.
 * Mac OS X >= 10.12, older versions do not provide `shared_mutex` in libc++
 
 Below are quick commands for the impatient. Detailed instructions can be found at [[Build]].
@@ -21,7 +22,7 @@ cmake --build Release
 
 The executable is at `Release/ccls`.
 
-You may use `-DSYSTEM_CLANG=on` if you have clang and llvm installed somewhere.
+You may use `-DSYSTEM_CLANG=on` if you have clang and llvm installed somewhere (can be a releases.llvm.org prebuilt archive, not necessarily installed via the system package manager).
 But caution is that you need to identify whether the clang library is compiled with `-DLLVM_ENABLE_RTTI=on`
 
 * Arch Linux