diff --git a/lib/krb5/an2ln_plugin.h b/lib/krb5/an2ln_plugin.h
index 98eafe897..89913b578 100644
--- a/lib/krb5/an2ln_plugin.h
+++ b/lib/krb5/an2ln_plugin.h
@@ -39,7 +39,7 @@
 #define KRB5_PLUGIN_AN2LN "an2ln"
 #define KRB5_PLUGIN_AN2LN_VERSION_0 0
 
-typedef krb5_error_code (*set_result_f)(void *, const char *);
+typedef krb5_error_code (KRB5_LIB_CALL *set_result_f)(void *, const char *);
 
 /** @struct krb5plugin_an2ln_ftable_desc
  *
@@ -81,9 +81,9 @@ typedef krb5_error_code (*set_result_f)(void *, const char *);
  */
 typedef struct krb5plugin_an2ln_ftable_desc {
     int			minor_version;
-    krb5_error_code	(*init)(krb5_context, void **);
-    void		(*fini)(void *);
-    krb5_error_code	(*an2ln)(void *, krb5_context, const char *,
+    krb5_error_code	(KRB5_LIB_CALL *init)(krb5_context, void **);
+    void		(KRB5_LIB_CALL *fini)(void *);
+    krb5_error_code	(KRB5_LIB_CALL *an2ln)(void *, krb5_context, const char *,
 	                         krb5_const_principal, set_result_f, void *);
 } krb5plugin_an2ln_ftable;
 
diff --git a/lib/krb5/aname_to_localname.c b/lib/krb5/aname_to_localname.c
index 5a47268fc..ed96ea3d4 100644
--- a/lib/krb5/aname_to_localname.c
+++ b/lib/krb5/aname_to_localname.c
@@ -36,9 +36,9 @@
 #include "db_plugin.h"
 
 /* Default plugin (DB using binary search of sorted text file) follows */
-static krb5_error_code an2ln_def_plug_init(krb5_context, void **);
-static void an2ln_def_plug_fini(void *);
-static krb5_error_code an2ln_def_plug_an2ln(void *, krb5_context, const char *,
+static krb5_error_code KRB5_LIB_CALL an2ln_def_plug_init(krb5_context, void **);
+static void KRB5_LIB_CALL an2ln_def_plug_fini(void *);
+static krb5_error_code KRB5_LIB_CALL an2ln_def_plug_an2ln(void *, krb5_context, const char *,
 					    krb5_const_principal, set_result_f,
 					    void *);
 
@@ -349,14 +349,14 @@ krb5_aname_to_localname(krb5_context context,
     return ret;
 }
 
-static krb5_error_code
+static krb5_error_code KRB5_LIB_CALL
 an2ln_def_plug_init(krb5_context context, void **ctx)
 {
     *ctx = NULL;
     return 0;
 }
 
-static void
+static void KRB5_LIB_CALL
 an2ln_def_plug_fini(void *ctx)
 {
 }
@@ -369,7 +369,7 @@ sorted_text_db_init_f(void *arg)
     (void) heim_db_register("sorted-text", NULL, &heim_sorted_text_file_dbtype);
 }
 
-static krb5_error_code
+static krb5_error_code KRB5_LIB_CALL
 an2ln_def_plug_an2ln(void *plug_ctx, krb5_context context,
 		     const char *rule,
 		     krb5_const_principal aname,
diff --git a/lib/krb5/db_plugin.h b/lib/krb5/db_plugin.h
index cb319a290..730c06095 100644
--- a/lib/krb5/db_plugin.h
+++ b/lib/krb5/db_plugin.h
@@ -60,8 +60,8 @@
  */
 typedef struct krb5plugin_db_ftable_desc {
     int			minor_version;
-    krb5_error_code	(*init)(krb5_context, void **);
-    void		(*fini)(void *);
+    krb5_error_code	(KRB5_LIB_CALL *init)(krb5_context, void **);
+    void		(KRB5_LIB_CALL *fini)(void *);
 } krb5plugin_db_ftable;
 
 #endif /* HEIMDAL_KRB5_DB_PLUGIN_H */
diff --git a/lib/krb5/kuserok.c b/lib/krb5/kuserok.c
index c6f887102..ace47da0b 100644
--- a/lib/krb5/kuserok.c
+++ b/lib/krb5/kuserok.c
@@ -55,7 +55,7 @@ struct plctx {
     krb5_boolean         result;
 };
 
-static krb5_error_code
+static krb5_error_code KRB5_LIB_CALL
 plcallback(krb5_context context, const void *plug, void *plugctx, void *userctx)
 {
     const krb5plugin_kuserok_ftable *locate = plug;
@@ -523,7 +523,7 @@ out:
  * Simple kuserok: check that the lname for the aname matches luser.
  */
 
-static krb5_error_code
+static krb5_error_code KRB5_LIB_CALL
 kuserok_simple_plug_f(void *plug_ctx, krb5_context context, const char *rule,
 		      unsigned int flags, const char *k5login_dir,
 		      const char *luser, krb5_const_principal principal,
@@ -546,7 +546,7 @@ kuserok_simple_plug_f(void *plug_ctx, krb5_context context, const char *rule,
  * directories.
  */
 
-static krb5_error_code
+static krb5_error_code KRB5_LIB_CALL
 kuserok_sys_k5login_plug_f(void *plug_ctx, krb5_context context,
 			   const char *rule, unsigned int flags,
 			   const char *k5login_dir, const char *luser,
@@ -588,7 +588,7 @@ kuserok_sys_k5login_plug_f(void *plug_ctx, krb5_context context,
  * Check ~luser/.k5login and/or ~/luser/.k5login.d
  */
 
-static krb5_error_code
+static krb5_error_code KRB5_LIB_CALL
 kuserok_user_k5login_plug_f(void *plug_ctx, krb5_context context,
 			    const char *rule, unsigned int flags,
 			    const char *k5login_dir, const char *luser,
@@ -669,7 +669,7 @@ kuserok_user_k5login_plug_f(void *plug_ctx, krb5_context context,
 #endif
 }
 
-static krb5_error_code
+static krb5_error_code KRB5_LIB_CALL
 kuserok_deny_plug_f(void *plug_ctx, krb5_context context, const char *rule,
 		    unsigned int flags, const char *k5login_dir,
 		    const char *luser, krb5_const_principal principal,
@@ -682,14 +682,14 @@ kuserok_deny_plug_f(void *plug_ctx, krb5_context context, const char *rule,
     return 0;
 }
 
-static krb5_error_code
+static krb5_error_code KRB5_LIB_CALL
 kuser_ok_null_plugin_init(krb5_context context, void **ctx)
 {
     *ctx = NULL;
     return 0;
 }
 
-static void
+static void KRB5_LIB_CALL
 kuser_ok_null_plugin_fini(void *ctx)
 {
     return;
diff --git a/lib/krb5/kuserok_plugin.h b/lib/krb5/kuserok_plugin.h
index 5b0be4a57..282381384 100644
--- a/lib/krb5/kuserok_plugin.h
+++ b/lib/krb5/kuserok_plugin.h
@@ -77,9 +77,9 @@
  */
 typedef struct krb5plugin_kuserok_ftable_desc {
     int			minor_version;
-    krb5_error_code	(*init)(krb5_context, void **);
-    void		(*fini)(void *);
-    krb5_error_code	(*kuserok)(void *, krb5_context, const char *,
+    krb5_error_code	(KRB5_LIB_CALL *init)(krb5_context, void **);
+    void		(KRB5_LIB_CALL *fini)(void *);
+    krb5_error_code	(KRB5_LIB_CALL *kuserok)(void *, krb5_context, const char *,
 				   unsigned int, const char *, const char *,
 				   krb5_const_principal,
 				   krb5_boolean *);
diff --git a/lib/krb5/plugin.c b/lib/krb5/plugin.c
index aebab534b..c15f9dd8b 100644
--- a/lib/krb5/plugin.c
+++ b/lib/krb5/plugin.c
@@ -551,7 +551,7 @@ struct iter_ctx {
     const char *name;
     int min_version;
     heim_array_t result;
-    krb5_error_code (*func)(krb5_context, const void *, void *, void *);
+    krb5_error_code (KRB5_LIB_CALL *func)(krb5_context, const void *, void *, void *);
     void *userctx;
     krb5_error_code ret;
 };
@@ -636,7 +636,7 @@ _krb5_plugin_run_f(krb5_context context,
 		   int min_version,
 		   int flags,
 		   void *userctx,
-		   krb5_error_code (*func)(krb5_context, const void *, void *, void *))
+		   krb5_error_code (KRB5_LIB_CALL *func)(krb5_context, const void *, void *, void *))
 {
     heim_string_t m = heim_string_create(module);
     heim_dict_t dict;