diff --git a/makefile_slinux b/makefile_slinux
index e5303ae1..3a76d92b 100644
--- a/makefile_slinux
+++ b/makefile_slinux
@@ -17,7 +17,7 @@ CC       = gcc
 CFLAGS = -I$(HDFROOT)/include -DHDF4 -DHDF5 -DNXXML $(NI) \
        -Ipsi/hardsup -I. \
        -fwritable-strings -DCYGNUS -DNONINTF -g $(DFORTIFY) \
-       -Wall -Wno-unused -Wno-comment -Wno-switch
+       -Wall -Wno-unused -Wno-comment -Wno-switch -Werror
 
 BINTARGET = bin
 EXTRA=nintf.o