diff --git a/assembler/configure.ac b/assembler/configure.ac
index 11382df1..a988605a 100644
--- a/assembler/configure.ac
+++ b/assembler/configure.ac
@@ -17,6 +17,16 @@ AC_PROG_CC
 AM_PROG_LEX
 AC_PROG_YACC
 
+WARN_CFLAGS=""
+if test "x$GCC" = "xyes"; then
+	WARN_CFLAGS="-Wall -Wpointer-arith -Wstrict-prototypes \
+	-Wmissing-prototypes -Wmissing-declarations \
+	-Wnested-externs -fno-strict-aliasing"
+	AC_DEFINE_UNQUOTED(HAVE_WARNING_CPP_DIRECTIVE,1,
+	[Can use #warning in C files])
+fi
+AC_SUBST(WARN_CFLAGS)
+
 # Checks for libraries.
 
 # Checks for header files.
diff --git a/assembler/src/Makefile.am b/assembler/src/Makefile.am
index baedab62..6c65e69f 100644
--- a/assembler/src/Makefile.am
+++ b/assembler/src/Makefile.am
@@ -1,5 +1,6 @@
 AM_YFLAGS = -d
 
+AM_CFLAGS= $(WARN_CFLAGS)
 bin_PROGRAMS = intel-gen4asm
 
 intel_gen4asm_SOURCES = \