diff --git a/scripts/configure b/scripts/configure
index 0441cac8..46b15491 100755
--- a/scripts/configure
+++ b/scripts/configure
@@ -7780,7 +7780,7 @@ case $target in
 
         case $target in
 	*x86_64*)
-	    CFLAGS="${CFLAGS} -m64 -fPIC"
+	    CFLAGS="${CFLAGS} -m64 -fPIC -Werror=implicit-function-declaration"
 	    ;;
     esac
     if test $usingOGL ; then
diff --git a/scripts/configure.in b/scripts/configure.in
index 6518f98f..83fd1c33 100644
--- a/scripts/configure.in
+++ b/scripts/configure.in
@@ -1359,7 +1359,7 @@ case $target in
     dnl 64-bit support for AMD Opteron
     case $target in
 	*x86_64*)
-	    CFLAGS="${CFLAGS} -m64 -fPIC"
+	    CFLAGS="${CFLAGS} -m64 -fPIC -Werror=implicit-function-declaration"
 	    ;;
     esac
     if test $usingOGL ; then