diff --git a/include/security/openpam.h b/include/security/openpam.h
index e26e962..5b5497f 100644
--- a/include/security/openpam.h
+++ b/include/security/openpam.h
@@ -42,6 +42,10 @@
  */
 #include <stdarg.h>
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /*
  * API extensions
  */
@@ -199,4 +203,8 @@ DATA_SET(_openpam_modules, _pam_module)
 #define PAM_MODULE_ENTRY(name)
 #endif
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif
diff --git a/include/security/pam_appl.h b/include/security/pam_appl.h
index a5b785f..f3e7e60 100644
--- a/include/security/pam_appl.h
+++ b/include/security/pam_appl.h
@@ -40,6 +40,10 @@
 #include <security/pam_types.h>
 #include <security/pam_constants.h>
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /*
  * XSSO 4.2.1, 6
  */
@@ -169,4 +173,8 @@ pam_set_mapped_username(pam_handle_t *_pamh,
 	char *_target_authn_domain);
 #endif /* 0 */
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif
diff --git a/include/security/pam_constants.h b/include/security/pam_constants.h
index 4aacf71..71d6ba8 100644
--- a/include/security/pam_constants.h
+++ b/include/security/pam_constants.h
@@ -37,6 +37,10 @@
 #ifndef _PAM_CONSTANTS_H_INCLUDED
 #define _PAM_CONSTANTS_H_INCLUDED
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /*
  * XSSO 5.2
  */
@@ -117,4 +121,8 @@ enum {
 	PAM_AUTHTOK_PROMPT		=  10		/* OpenPAM extension */
 };
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif
diff --git a/include/security/pam_modules.h b/include/security/pam_modules.h
index 9340e77..35c8eb9 100644
--- a/include/security/pam_modules.h
+++ b/include/security/pam_modules.h
@@ -41,6 +41,10 @@
 #include <security/pam_constants.h>
 #include <security/openpam.h>
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /*
  * XSSO 4.2.2, 6
  */
@@ -137,4 +141,8 @@ pam_sm_set_mapped_username(pam_handle_t *_pamh,
 
 #endif /* 0 */
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif
diff --git a/include/security/pam_types.h b/include/security/pam_types.h
index 729f962..d8ba80b 100644
--- a/include/security/pam_types.h
+++ b/include/security/pam_types.h
@@ -37,6 +37,10 @@
 #ifndef _PAM_TYPES_H_INCLUDED
 #define _PAM_TYPES_H_INCLUDED
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /*
  * XSSO 5.1.1
  */
@@ -65,4 +69,8 @@ struct pam_conv {
 struct pam_handle;
 typedef struct pam_handle pam_handle_t;
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif