Hi, I'm a new org user, and I'm sorry if I'm missing something obvious. When executing a C code snippet with org-babel, that contains a math function, I get the famous "undefined reference" errors. I tried adding ":flags -lm", but that doesn't help. Looking at the code, it seems the -lm flag is inserted in the wrong place, before the source file. An easy change would be in line 147 of ob-C.el version 8.3.4-634, moving "flags" to after the source file. This seems to work, but I don't know if it would break anything else. A minimal working example, attached, includes the following snippet: #+BEGIN_SRC C :includes '( ) :flags -lm int i=9; printf("%d\n",(int)sqrt(i)); #+END_SRC Note the issue disappears if constants are directly used rather than variables, presumably because the function call is optimized away entirely. Any thoughts are appreciated. Oz