diff -urNad libgsm-1.0.10~/inc/gsm.h libgsm-1.0.10/inc/gsm.h
--- libgsm-1.0.10~/inc/gsm.h	2007-11-01 15:37:52.000000000 +0100
+++ libgsm-1.0.10/inc/gsm.h	2007-11-01 15:44:52.000000000 +0100
@@ -54,6 +54,10 @@
 #define	GSM_OPT_FRAME_INDEX	5
 #define	GSM_OPT_FRAME_CHAIN	6
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 extern gsm  gsm_create 	GSM_P((void));
 extern void gsm_destroy GSM_P((gsm));	
 
@@ -66,6 +70,10 @@
 extern int  gsm_explode GSM_P((gsm, gsm_byte   *, gsm_signal *));
 extern void gsm_implode GSM_P((gsm, gsm_signal *, gsm_byte   *));
 
+#ifdef __cplusplus
+}
+#endif
+
 #undef	GSM_P
 
 #endif	/* GSM_H */