diff --git a/Dockerfile b/Dockerfile
index 8682454..4dc1943 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -16,15 +16,15 @@ RUN apk --no-cache add \
   icu-dev \
   inotify-tools-dev
 
-ENV SHA256_SUM_DOVECOT=db5abcd87d7309659ea6b45b2cb6ee9c5f97486b2b719a5dd05a759e1f6a5c51
-ENV DOVECOT_FILENAME=dovecot-2.3.19.1.tar.gz
+ENV SHA256_SUM_DOVECOT=caa832eb968148abdf35ee9d0f534b779fa732c0ce4a913d9ab8c3469b218552
+ENV DOVECOT_FILENAME=dovecot-2.3.20.tar.gz
 RUN wget https://www.dovecot.org/releases/2.3/$DOVECOT_FILENAME
 RUN echo "$SHA256_SUM_DOVECOT  $DOVECOT_FILENAME" | sha256sum -c - || exit 1
 RUN mkdir /tmp/dovecot
 RUN tar xzf $DOVECOT_FILENAME -C /tmp/dovecot --strip 1
 
-ENV SHA256_SUM_PIGEONHOLE=637709a83fb1338c918e5398049f96b7aeb5ae00696794ed1e5a4d4c0ca3f688
-ENV PIGEONHOLE_FILENAME=dovecot-2.3-pigeonhole-0.5.19.tar.gz
+ENV SHA256_SUM_PIGEONHOLE=ae32bd4870ea2c1328ae09ba206e9ec12128046d6afca52fbbc9ef7f75617c98
+ENV PIGEONHOLE_FILENAME=dovecot-2.3-pigeonhole-0.5.20.tar.gz
 RUN wget https://pigeonhole.dovecot.org/releases/2.3/$PIGEONHOLE_FILENAME
 RUN echo "$SHA256_SUM_PIGEONHOLE  $PIGEONHOLE_FILENAME" | sha256sum -c - || exit 1
 RUN mkdir /tmp/pigeonhole