diff --git a/requirements.txt b/requirements.txt
index 4ffe4b6..d0f7157 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -20,7 +20,7 @@ itsdangerous==0.24        # via flask
 jinja2==2.9.6             # via flask
 markupsafe==1.0           # via jinja2
 marshmallow-jsonapi==0.15.1  # via -r requirements.in
-marshmallow==2.13.6       # via marshmallow-jsonapi
+marshmallow==2.15.1       # via marshmallow-jsonapi
 mccabe==0.6.1             # via flake8
 mock==2.0.0               # via -r requirements.in
 pbr==3.1.1                # via mock