diff --git a/src/multimodule/poi/java9/module-info.java b/src/multimodule/poi/java9/module-info.java
index a34988980b..31ef8e1ff9 100644
--- a/src/multimodule/poi/java9/module-info.java
+++ b/src/multimodule/poi/java9/module-info.java
@@ -21,6 +21,7 @@ module org.apache.poi.poi {
     requires commons.math3;
     requires SparseBitSet;
     requires commons.logging;
+    requires org.slf4j;
     requires java.logging;
     requires java.desktop;