diff --git a/Dockerfile b/Dockerfile
index c4f3a3e..7522a11 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -11,7 +11,13 @@ WORKDIR /var/app
 
 COPY requirements.txt ./
 
-RUN pip install --no-cache-dir --upgrade --requirement requirements.txt
+# Required to build greenlet on Alpine, dependency of SQLAlchemy 1.4.
+RUN apk add --no-cache \
+        --virtual .build-deps \
+        g++ gcc musl-dev \
+    && pip install --no-cache-dir --upgrade \
+        --requirement requirements.txt \
+    && apk del .build-deps
 
 USER 10000:10001