diff --git a/Zend/zend_exceptions.c b/Zend/zend_exceptions.c
index 14ae75e..c7f157c 100644
--- a/Zend/zend_exceptions.c
+++ b/Zend/zend_exceptions.c
@@ -560,7 +560,7 @@ ZEND_METHOD(exception, getPrevious)
 	RETURN_ZVAL(previous, 1, 0);
 }
 
-int zend_spprintf(char **message, int max_len, char *format, ...) /* {{{ */
+int zend_spprintf(char **message, int max_len, const char *format, ...) /* {{{ */
 {
 	va_list arg;
 	int len;
@@ -732,7 +732,7 @@ ZEND_API zend_class_entry *zend_get_error_exception(TSRMLS_D) /* {{{ */
 }
 /* }}} */
 
-ZEND_API zval * zend_throw_exception(zend_class_entry *exception_ce, char *message, long code TSRMLS_DC) /* {{{ */
+ZEND_API zval * zend_throw_exception(zend_class_entry *exception_ce, const char *message, long code TSRMLS_DC) /* {{{ */
 {
 	zval *ex;
 
@@ -760,7 +760,7 @@ ZEND_API zval * zend_throw_exception(zend_class_entry *exception_ce, char *messa
 }
 /* }}} */
 
-ZEND_API zval * zend_throw_exception_ex(zend_class_entry *exception_ce, long code TSRMLS_DC, char *format, ...) /* {{{ */
+ZEND_API zval * zend_throw_exception_ex(zend_class_entry *exception_ce, long code TSRMLS_DC, const char *format, ...) /* {{{ */
 {
 	va_list arg;
 	char *message;
@@ -775,7 +775,7 @@ ZEND_API zval * zend_throw_exception_ex(zend_class_entry *exception_ce, long cod
 }
 /* }}} */
 
-ZEND_API zval * zend_throw_error_exception(zend_class_entry *exception_ce, char *message, long code, int severity TSRMLS_DC) /* {{{ */
+ZEND_API zval * zend_throw_error_exception(zend_class_entry *exception_ce, const char *message, long code, int severity TSRMLS_DC) /* {{{ */
 {
 	zval *ex = zend_throw_exception(exception_ce, message, code TSRMLS_CC);
 	zend_update_property_long(default_exception_ce, ex, "severity", sizeof("severity")-1, severity TSRMLS_CC);
diff --git a/Zend/zend_exceptions.h b/Zend/zend_exceptions.h
index 8263353..81c8a1f 100644
--- a/Zend/zend_exceptions.h
+++ b/Zend/zend_exceptions.h
@@ -40,12 +40,12 @@ ZEND_API void zend_register_default_classes(TSRMLS_D);
 
 /* exception_ce   NULL or zend_exception_get_default() or a derived class
  * message        NULL or the message of the exception */
-ZEND_API zval * zend_throw_exception(zend_class_entry *exception_ce, char *message, long code TSRMLS_DC);
-ZEND_API zval * zend_throw_exception_ex(zend_class_entry *exception_ce, long code TSRMLS_DC, char *format, ...);
+ZEND_API zval * zend_throw_exception(zend_class_entry *exception_ce, const char *message, long code TSRMLS_DC);
+ZEND_API zval * zend_throw_exception_ex(zend_class_entry *exception_ce, long code TSRMLS_DC, const char *format, ...);
 ZEND_API void zend_throw_exception_object(zval *exception TSRMLS_DC);
 ZEND_API void zend_clear_exception(TSRMLS_D);
 
-ZEND_API zval * zend_throw_error_exception(zend_class_entry *exception_ce, char *message, long code, int severity TSRMLS_DC);
+ZEND_API zval * zend_throw_error_exception(zend_class_entry *exception_ce, const char *message, long code, int severity TSRMLS_DC);
 
 extern ZEND_API void (*zend_throw_exception_hook)(zval *ex TSRMLS_DC);
 
@@ -53,7 +53,7 @@ extern ZEND_API void (*zend_throw_exception_hook)(zval *ex TSRMLS_DC);
 ZEND_API void zend_exception_error(zval *exception, int severity TSRMLS_DC);
 
 /* do not export, in php it's available thru spprintf directly */
-int zend_spprintf(char **message, int max_len, char *format, ...);
+int zend_spprintf(char **message, int max_len, const char *format, ...);
 
 END_EXTERN_C()