diff --git a/poi-ooxml/src/main/java/org/apache/poi/openxml4j/opc/ZipPackage.java b/poi-ooxml/src/main/java/org/apache/poi/openxml4j/opc/ZipPackage.java
index 9c030584b9..9cef016c02 100644
--- a/poi-ooxml/src/main/java/org/apache/poi/openxml4j/opc/ZipPackage.java
+++ b/poi-ooxml/src/main/java/org/apache/poi/openxml4j/opc/ZipPackage.java
@@ -327,7 +327,7 @@ public final class ZipPackage extends OPCPackage {
 
             if (partList.containsKey(partName)) {
                 throw new InvalidFormatException(
-                    "A part with the name '"+partName+"' already exist : Packages shall not contain equivalent part names " +
+                    "A part with the name '"+partName+"' already exists : Packages shall not contain equivalent part names " +
                     "and package implementers shall neither create nor recognize packages with equivalent part names. [M1.12]");
             }