diff --git a/libs/freetdm/Makefile.in b/libs/freetdm/Makefile.in
index a595b9355e..3a1f4eb2d9 100644
--- a/libs/freetdm/Makefile.in
+++ b/libs/freetdm/Makefile.in
@@ -29,7 +29,15 @@
 # NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 # SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-CFLAGS=@COMP_VENDOR_CFLAGS@ @DEFS@
+CC = @CC@
+CPP = @CPP@
+CPPFLAGS = @CPPFLAGS@
+CXX = @CXX@
+CXXCPP = @CXXCPP@
+CXXFLAGS = @CXXFLAGS@
+DEFS = @DEFS@
+DEPDIR = @DEPDIR@
+CFLAGS=@CFLAGS@ @COMP_VENDOR_CFLAGS@ @DEFS@
 SRC=src
 SOURCES=\
 $(SRC)/hashtable.c \