diff --git a/CMakeLists.txt b/CMakeLists.txt
index 12f7e1b..1f7642f 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -158,6 +158,7 @@
 
 CHECK_FUNCTION_EXISTS(bzero HAVE_BZERO)
 CHECK_FUNCTION_EXISTS(fork HAVE_FORK)
+CHECK_FUNCTION_EXISTS(getenv HAVE_GETENV)
 CHECK_FUNCTION_EXISTS(malloc HAVE_MALLOC)
 CHECK_FUNCTION_EXISTS(memset HAVE_MEMSET)
 CHECK_FUNCTION_EXISTS(realloc HAVE_REALLOC)