diff --git a/docker/Dockerfile b/docker/Dockerfile
index bf37d6d88bf..1fe380552ae 100644
--- a/docker/Dockerfile
+++ b/docker/Dockerfile
@@ -17,8 +17,11 @@ RUN git config --system --add safe.directory "*" \
 # validate openocd-esp32 (it dynamically links libusb-1.0.so.0); without
 # it idf_tools.py rejects the openocd install with exit 127 and aborts
 # the whole framework setup.
+# ccache speeds up repeat ESP-IDF compiles (enabled via IDF_CCACHE_ENABLE);
+# ESP-IDF silently skips it when the binary isn't on PATH, so it must be
+# present in the image for the dashboard/Device Builder to benefit.
 RUN apt-get update \
-    && apt-get install -y --no-install-recommends build-essential libusb-1.0-0 \
+    && apt-get install -y --no-install-recommends build-essential libusb-1.0-0 ccache \
     && rm -rf /var/lib/apt/lists/*
 
 ENV PIP_DISABLE_PIP_VERSION_CHECK=1