diff --git a/CMakeLists.txt b/CMakeLists.txt
index 6fa48dd967..533ef5a2d0 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -214,6 +214,8 @@ check_function_exists( setenv HAVE_POSIX_SETENV )
 check_function_exists( symlink ERT_HAVE_SYMLINK )
 check_function_exists( timegm HAVE_TIMEGM )
 check_function_exists( usleep HAVE__USLEEP )
+check_function_exists( unlink HAVE_POSIX_UNLINK )
+check_function_exists( _unlink HAVE_WINDOWS_UNLINK )
 
 check_symbol_exists(_tzname time.h HAVE_WINDOWS_TZNAME)
 check_symbol_exists( tzname time.h HAVE_TZNAME)
@@ -221,7 +223,6 @@ check_symbol_exists( tzname time.h HAVE_TZNAME)
 check_include_file(execinfo.h HAVE_EXECINFO)
 check_include_file(getopt.h   ERT_HAVE_GETOPT)
 check_include_file(unistd.h   ERT_HAVE_UNISTD)
-check_include_file(io.h       ERT_HAVE_IO)
 
 check_type_size(time_t SIZE_OF_TIME_T)
 if (${SIZE_OF_TIME_T} EQUAL 8)
diff --git a/lib/build_config.h.in b/lib/build_config.h.in
index 14bdc174b5..0e9b1ff847 100644
--- a/lib/build_config.h.in
+++ b/lib/build_config.h.in
@@ -28,6 +28,8 @@
 #cmakedefine HAVE_CHMOD
 #cmakedefine HAVE_MODE_T
 #cmakedefine HAVE_CXX_SHARED_PTR
+#cmakedefine HAVE_POSIX_UNLINK
+#cmakedefine HAVE_WINDOWS_UNLINK
 
 
 #cmakedefine HAVE_WINDOWS_GET_TEMP_PATH
diff --git a/lib/include/ert/util/util_unlink.h b/lib/include/ert/util/util_unlink.h
index 6023aa8990..646e93aebc 100644
--- a/lib/include/ert/util/util_unlink.h
+++ b/lib/include/ert/util/util_unlink.h
@@ -20,11 +20,17 @@
 #ifndef ERT_UTIL_UNLINK_H
 #define ERT_UTIL_UNLINK_H
 
+#include "ert/util/build_config.h"
+
 #ifdef __cplusplus
 extern "C" {
 #endif
-  
+
+#if defined(HAVE_POSIX_UNLINK) || defined(HAVE_WINDOWS_UNLINK)
+
   int util_unlink(const char * filename);
+
+#endif
   
 #ifdef __cplusplus
 }
diff --git a/lib/util/hash.c b/lib/util/hash.c
index 0237da18f1..c8a9de62bd 100644
--- a/lib/util/hash.c
+++ b/lib/util/hash.c
@@ -87,10 +87,6 @@ typedef struct hash_sort_node {
 /*                          locking                              */
 /*****************************************************************/
 #ifdef HAVE_PTHREAD
-static void __hash_deadlock_abort(hash_type * hash) {
-  util_abort("%s: A deadlock condition has been detected in the hash routine - and the program will abort.\n", __func__);
-}
-
 
 static void __hash_rdlock(hash_type * hash) {
   int lock_error = pthread_rwlock_tryrdlock( &hash->rwlock );
diff --git a/lib/util/util_unlink.c b/lib/util/util_unlink.c
index 5faebc82bc..1539065546 100644
--- a/lib/util/util_unlink.c
+++ b/lib/util/util_unlink.c
@@ -16,22 +16,22 @@
    for more details.
 */
 
+#include "ert/util/build_config.h"
 
-#if defined(ERT_HAVE_UNISTD)
-  #include <unistd.h>
-#elif defined(ERT_HAVE_IO)
-  #include <io.h>
-#else
-  #include <ert/util/util.h>
-#endif
+#if defined(HAVE_WINDOWS_UNLINK)
+
+#include <io.h>
 
 int util_unlink(const char * filename) {
-#if defined(ERT_HAVE_UNISTD)
- return unlink(filename);
-#elif defined(ERT_HAVE_IO)
  return _unlink(filename);
-#else
- util_abort("%s: No unlink functionality available.\n", __func__);
- return -1;
-#endif
 }
+
+#elif defined(HAVE_POSIX_UNLINK)
+
+#include <unistd.h>
+
+int util_unlink(const char * filename) {
+ return unlink(filename);
+}
+
+#endif