diff --git a/0.21/alpine/Dockerfile b/0.21/alpine/Dockerfile
index 22774bf..413538f 100644
--- a/0.21/alpine/Dockerfile
+++ b/0.21/alpine/Dockerfile
@@ -17,7 +17,7 @@ RUN mkdir -p ${BERKELEYDB_PREFIX}
 
 WORKDIR /${BERKELEYDB_VERSION}/build_unix
 
-RUN ../dist/configure --enable-cxx --disable-shared --with-pic --prefix=${BERKELEYDB_PREFIX}
+RUN CFLAGS=-Wno-error=implicit-function-declaration ../dist/configure --enable-cxx --disable-shared --with-pic --prefix=${BERKELEYDB_PREFIX}
 RUN make -j4
 RUN make install
 RUN rm -rf ${BERKELEYDB_PREFIX}/docs