diff --git a/base-buster/Dockerfile b/base-buster/Dockerfile
--- a/base-buster/Dockerfile
+++ b/base-buster/Dockerfile
@@ -115,6 +115,12 @@
 VOLUME ${AGENT_WORKDIR}
 WORKDIR /home/${user}
 
+# install emscripten required for generating tree-sitter WASM module in swh-search
+RUN cd /tmp && git clone https://github.com/emscripten-core/emsdk.git && cd emsdk \
+  && ./emsdk install latest && ./emsdk activate latest
+
+ENV PATH="${PATH}:/tmp/emsdk/upstream/emscripten"
+
 ## ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ##
 
 ## vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv ##