diff --git a/src/ngx_http_lua_headers.c b/src/ngx_http_lua_headers.c
index 0af56f66ad..da0016c903 100644
--- a/src/ngx_http_lua_headers.c
+++ b/src/ngx_http_lua_headers.c
@@ -444,6 +444,8 @@ ngx_http_lua_ngx_resp_get_headers(lua_State *L)
     ngx_list_part_t    *part;
     ngx_table_elt_t    *header;
     ngx_http_request_t *r;
+    ngx_http_lua_ctx_t *ctx;
+    ngx_int_t           rc;
     u_char             *lowcase_key = NULL;
     size_t              lowcase_key_sz = 0;
     ngx_uint_t          i;
@@ -475,6 +477,22 @@ ngx_http_lua_ngx_resp_get_headers(lua_State *L)
         return luaL_error(L, "no request object found");
     }
 
+    ctx = ngx_http_get_module_ctx(r, ngx_http_lua_module);
+    if (ctx == NULL) {
+        return luaL_error(L, "no ctx found");
+    }
+
+    if (!ctx->headers_set) {
+        rc = ngx_http_lua_set_content_type(r);
+        if (rc != NGX_OK) {
+            return luaL_error(L,
+                              "failed to set default content type: %d",
+                              (int) rc);
+        }
+        
+        ctx->headers_set = 1;
+    }
+
     ngx_http_lua_check_fake_request(L, r);
 
     part = &r->headers_out.headers.part;
@@ -603,12 +621,19 @@ ngx_http_lua_ngx_header_get(lua_State *L)
     ngx_uint_t                   i;
     size_t                       len;
     ngx_http_lua_loc_conf_t     *llcf;
+    ngx_http_lua_ctx_t          *ctx;
+    ngx_int_t                    rc;
 
     r = ngx_http_lua_get_req(L);
     if (r == NULL) {
         return luaL_error(L, "no request object found");
     }
 
+    ctx = ngx_http_get_module_ctx(r, ngx_http_lua_module);
+    if (ctx == NULL) {
+        return luaL_error(L, "no ctx found");
+    }
+
     ngx_http_lua_check_fake_request(L, r);
 
     /* we skip the first argument that is the table */
@@ -640,6 +665,17 @@ ngx_http_lua_ngx_header_get(lua_State *L)
 
     key.len = len;
 
+    if (!ctx->headers_set) {
+        rc = ngx_http_lua_set_content_type(r);
+        if (rc != NGX_OK) {
+            return luaL_error(L,
+                              "failed to set default content type: %d",
+                              (int) rc);
+        }
+
+        ctx->headers_set = 1;
+    }
+
     return ngx_http_lua_get_output_header(L, r, &key);
 }
 
diff --git a/t/016-resp-header.t b/t/016-resp-header.t
index 179b411b8c..1fae2922a5 100644
--- a/t/016-resp-header.t
+++ b/t/016-resp-header.t
@@ -8,7 +8,7 @@ use Test::Nginx::Socket::Lua;
 
 repeat_each(2);
 
-plan tests => repeat_each() * (blocks() * 3 + 38);
+plan tests => repeat_each() * (blocks() * 3 + 41);
 
 #no_diff();
 no_long_string();
@@ -1441,3 +1441,71 @@ Content-Type: ; blah
 test
 --- no_error_log
 [error]
+
+
+
+=== TEST 69: return the matched content-type instead of default_type
+--- http_config
+types {
+    image/png png;
+}
+--- config
+location /set/ {
+     default_type text/html;
+     content_by_lua_block {
+       ngx.say(ngx.header["content-type"])
+   }
+}
+--- request
+GET /set/hello.png
+--- response_headers
+Content-Type: image/png
+--- response_body
+image/png
+--- no_error_log
+[error]
+
+
+
+=== TEST 70: always return the matched content-type
+--- config
+    location /set/ {
+        default_type "image/png";
+        content_by_lua_block {
+            ngx.say(ngx.header["content-type"])
+            ngx.say(ngx.header["content-type"])
+        }
+    }
+--- request
+GET /set/hello.png
+--- response_headers
+Content-Type: image/png
+--- response_body
+image/png
+image/png
+--- no_error_log
+[error]
+
+
+
+=== TEST 71: return the matched content-type after ngx.resp.get_headers()
+--- http_config
+types {
+    image/png png;
+}
+--- config
+    location /set/ {
+        default_type text/html;
+        content_by_lua_block {
+            local h = ngx.resp.get_headers()
+            ngx.say(h["content-type"])
+        }
+    }
+--- request
+GET /set/hello.png
+--- response_headers
+Content-Type: image/png
+--- response_body
+image/png
+--- no_error_log
+[error]