diff --git a/ci/scripts/java_build.sh b/ci/scripts/java_build.sh
index 0fa1edab429..212ec6eb114 100755
--- a/ci/scripts/java_build.sh
+++ b/ci/scripts/java_build.sh
@@ -72,9 +72,6 @@ if [ $ARROW_JAVA_SKIP_GIT_PLUGIN ]; then
   mvn="${mvn} -Dmaven.gitcommitid.skip=true"
 fi
 
-# Use `2 * ncores` threads
-mvn="${mvn} -T 2C"
-
 # https://github.com/apache/arrow/issues/41429
 # TODO: We want to out-of-source build. This is a workaround. We copy
 # all needed files to the build directory from the source directory
@@ -98,10 +95,12 @@ if [ "${ARROW_JAVA_JNI}" = "ON" ]; then
   mvn="${mvn} -Darrow.cpp.build.dir=${java_jni_dist_dir} -Parrow-jni"
 fi
 
-${mvn} clean install
+# Use `2 * ncores` threads
+${mvn} -T 2C clean install
 
 if [ "${BUILD_DOCS_JAVA}" == "ON" ]; then
   # HTTP pooling is turned of to avoid download issues https://issues.apache.org/jira/browse/ARROW-11633
+  # GH-43378: Maven site plugins not compatible with multithreading
   mkdir -p ${build_dir}/docs/java/reference
   ${mvn} -Dcheckstyle.skip=true -Dhttp.keepAlive=false -Dmaven.wagon.http.pool=false clean install site
   rsync -a target/site/apidocs/ ${build_dir}/docs/java/reference