diff --git a/src/api/yajl_gen.h b/src/api/yajl_gen.h
index 36593e97..5ae4c5c7 100644
--- a/src/api/yajl_gen.h
+++ b/src/api/yajl_gen.h
@@ -114,7 +114,7 @@ extern "C" {
      *
      *  \returns an allocated handle on success, NULL on failure (bad params)
      */
-    yajl_gen YAJL_API yajl_gen_alloc2(yajl_print_t callback,
+    yajl_gen YAJL_API yajl_gen_alloc2(const yajl_print_t callback,
                                       const yajl_gen_config * config,
                                       const yajl_alloc_funcs * allocFuncs,
                                       void * ctx);
diff --git a/src/yajl_encode.c b/src/yajl_encode.c
index c3b02ed8..da216ab6 100644
--- a/src/yajl_encode.c
+++ b/src/yajl_encode.c
@@ -48,7 +48,7 @@ void
 yajl_string_encode(yajl_buf buf, const unsigned char * str,
                    unsigned int len)
 {
-    yajl_string_encode2((yajl_print_t) &yajl_buf_append, buf, str, len);
+    yajl_string_encode2((const yajl_print_t) &yajl_buf_append, buf, str, len);
 }
 
 void
diff --git a/src/yajl_encode.h b/src/yajl_encode.h
index 3f5b2363..af6878f0 100644
--- a/src/yajl_encode.h
+++ b/src/yajl_encode.h
@@ -36,7 +36,7 @@
 #include "yajl_buf.h"
 #include "api/yajl_gen.h"
 
-void yajl_string_encode2(yajl_print_t printer,
+void yajl_string_encode2(const yajl_print_t printer,
                          void * ctx,
                          const unsigned char * str,
                          unsigned int length);
diff --git a/src/yajl_gen.c b/src/yajl_gen.c
index 8b7fce2c..7d7becc9 100644
--- a/src/yajl_gen.c
+++ b/src/yajl_gen.c
@@ -70,7 +70,7 @@ yajl_gen_alloc(const yajl_gen_config * config,
 }
 
 yajl_gen
-yajl_gen_alloc2(yajl_print_t callback,
+yajl_gen_alloc2(const yajl_print_t callback,
                 const yajl_gen_config * config,
                 const yajl_alloc_funcs * afs,
                 void * ctx)