diff --git a/com.oracle.truffle.r.native/fficall/src/truffle_common/base_rffi.c b/com.oracle.truffle.r.native/fficall/src/truffle_common/base_rffi.c
index 17c0363e6cc98c9bee698420babe26fc6d70f154..db79b2215ba6b5029038ba6705ce42c0bb802a79 100644
--- a/com.oracle.truffle.r.native/fficall/src/truffle_common/base_rffi.c
+++ b/com.oracle.truffle.r.native/fficall/src/truffle_common/base_rffi.c
@@ -108,13 +108,9 @@ void call_base_strtol(void (*call_setresult)(long result, int cerrno), char *s,
 	call_setresult(rc, errno);
 }
 
-#include <zlib.h>
-#include <bzlib.h>
-#ifdef HAVE_PCRE_PCRE_H
-# include <pcre/pcre.h>
-#else
-# include <pcre.h>
-#endif
+extern const char * pcre_version();
+extern const char * zlibVersion();
+
 void call_base_eSoftVersion(void (*call_eSoftVersion_setfields)(char *zlibVersion, char *pcreVersion)) {
 
     char sZlibVersion[256], sPcreVersion[256];