diff --git a/src/blif2BSpice.c b/src/blif2BSpice.c
index 95414d6..3e7ef45 100644
--- a/src/blif2BSpice.c
+++ b/src/blif2BSpice.c
@@ -13,6 +13,7 @@
 #include <stdio.h>
 #include <string.h>
 #include <stdlib.h>
+#include <unistd.h>
 #include <math.h>
 #include <ctype.h>
 #include <float.h>
@@ -28,10 +29,6 @@
 #define LengthOfLine    	16384
 #define LengthOfNodeName  	512
 
-/* getopt stuff */
-extern	int	optind, getopt();
-extern	char	*optarg;
-
 void ReadNetlistAndConvert(FILE *, FILE *, char *, FILE *,
 		char *, char *, char *, int);
 void CleanupString(char text[]);
diff --git a/src/blif2Verilog.c b/src/blif2Verilog.c
index 78df6cb..932f819 100644
--- a/src/blif2Verilog.c
+++ b/src/blif2Verilog.c
@@ -10,6 +10,7 @@
 #include <stdio.h>
 #include <string.h>
 #include <stdlib.h>
+#include <unistd.h>
 #include <math.h>
 #include <ctype.h>
 #include <float.h>
@@ -25,10 +26,6 @@
 #define LengthOfLine    	16384
 #define LengthOfNodeName	512
 
-/* getopt stuff */
-extern	int	optind, getopt();
-extern	char	*optarg;
-
 #define INPUT	0
 #define OUTPUT	1