diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9eab1bf..957b9a8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,8 @@
 ### Dependencies
 * Updated Jackson to 2.20.0 (#106)
 
+### Fix
+* Prevent potential off-by-1 error in internal `mapOf()` helper (#107)
 
 ## 1.5.2 (2025-07-16)
 
diff --git a/src/main/java/de/stklcode/jvault/connector/HTTPVaultConnector.java b/src/main/java/de/stklcode/jvault/connector/HTTPVaultConnector.java
index c550273..5d2e9c8 100644
--- a/src/main/java/de/stklcode/jvault/connector/HTTPVaultConnector.java
+++ b/src/main/java/de/stklcode/jvault/connector/HTTPVaultConnector.java
@@ -732,7 +732,7 @@ public class HTTPVaultConnector implements VaultConnector {
      */
     private static Map<String, Object> mapOf(Object... keyValues) {
         Map<String, Object> map = new HashMap<>(keyValues.length / 2, 1);
-        for (int i = 0; i < keyValues.length; i = i + 2) {
+        for (int i = 0; i < keyValues.length - 1; i = i + 2) {
             Object key = keyValues[i];
             Object val = keyValues[i + 1];
             if (key instanceof String && val != null) {