diff --git a/doc/how-to-build.txt b/doc/how-to-build.txt
index 17cf4212..2bbd5310 100644
--- a/doc/how-to-build.txt
+++ b/doc/how-to-build.txt
@@ -19,9 +19,13 @@ Required for Fail*:
    <http://akut.aspectc.org>.  Make sure you use the 64-bit version if running
    in a 64-bit environment.
  - optional:
-   * LLVM 3.3 (needed for several importers in tools/import-trace)
+   * LLVM 3.3 or 3.4 (needed for several importers in tools/import-trace)
      (compiles/links with 3.1 or 3.2, but fails to properly import information
      from ELF binaries not compiled with -ffunction-sections)
+     -  configured with, e.g., --enable-optimized --disable-assertions
+        --disable-werror
+     -  built with "make REQUIRES_RTTI=1" (the Debian/Ubuntu packages already
+        come built this way)
    * a MySQL 5.0+ or MariaDB 5.1+ (MariaDB 5.5 recommended) server
 
 
diff --git a/src/core/util/llvmdisassembler/CMakeLists.txt b/src/core/util/llvmdisassembler/CMakeLists.txt
index 80f52b1d..3fe2a89e 100644
--- a/src/core/util/llvmdisassembler/CMakeLists.txt
+++ b/src/core/util/llvmdisassembler/CMakeLists.txt
@@ -11,8 +11,7 @@ set(SRCS
 
 include(FindLLVM)
 
-# compiling without -fno-rtti fails even when LLVM is not built with that flag
-set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${LLVM_CXX_FLAGS} -fno-rtti" )
+set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${LLVM_CXX_FLAGS}" )
 
 add_library(fail-llvmdisassembler ${SRCS})
 target_link_libraries(fail-llvmdisassembler fail-sal)