diff --git a/java/android/OlmLibSdk/olm-sdk/src/androidTest/java/org/matrix/olm/OlmUtilityTest.java b/java/android/OlmLibSdk/olm-sdk/src/androidTest/java/org/matrix/olm/OlmUtilityTest.java
index e483d71..d4c3382 100644
--- a/java/android/OlmLibSdk/olm-sdk/src/androidTest/java/org/matrix/olm/OlmUtilityTest.java
+++ b/java/android/OlmLibSdk/olm-sdk/src/androidTest/java/org/matrix/olm/OlmUtilityTest.java
@@ -86,12 +86,18 @@ public class OlmUtilityTest {
         assertTrue(isVerified);
         assertTrue(String.valueOf(errorMsg).isEmpty());
 
-        // check a bad signature is detected and the error message is not empty
+        // check a bad signature is detected => errorMsg = BAD_MESSAGE_MAC
         String badSignature = "Bad signature Bad signature Bad signature..";
         isVerified = utility.verifyEd25519Signature(badSignature, fingerPrintKey, message, errorMsg);
         assertFalse(isVerified);
         assertFalse(String.valueOf(errorMsg).isEmpty());
 
+        // check bad fingerprint size => errorMsg = INVALID_BASE64
+        String badSizeFingerPrintKey = fingerPrintKey.substring(fingerPrintKey.length()/2);
+        isVerified = utility.verifyEd25519Signature(messageSignature, badSizeFingerPrintKey, message, errorMsg);
+        assertFalse(isVerified);
+        assertFalse(String.valueOf(errorMsg).isEmpty());
+
         utility.releaseUtility();
         account.releaseAccount();
     }
diff --git a/java/android/OlmLibSdk/olm-sdk/src/main/jni/olm_utility.cpp b/java/android/OlmLibSdk/olm-sdk/src/main/jni/olm_utility.cpp
index bd93de1..19a045b 100644
--- a/java/android/OlmLibSdk/olm-sdk/src/main/jni/olm_utility.cpp
+++ b/java/android/OlmLibSdk/olm-sdk/src/main/jni/olm_utility.cpp
@@ -121,6 +121,7 @@ JNIEXPORT jstring OLM_UTILITY_FUNC_DEF(verifyEd25519SignatureJni)(JNIEnv *env, j
         size_t keyLength = (size_t)env->GetStringUTFLength(aKey);
         size_t messageLength = (size_t)env->GetStringUTFLength(aMessage);
         LOGD(" ## verifyEd25519SignatureJni(): signatureLength=%lu keyLength=%lu messageLength=%lu",static_cast<long unsigned int>(signatureLength),static_cast<long unsigned int>(keyLength),static_cast<long unsigned int>(messageLength));
+        LOGD(" ## verifyEd25519SignatureJni(): key=%s",keyPtr);
 
         size_t result = olm_ed25519_verify(utilityPtr,
                                            (void const *)keyPtr,
@@ -132,7 +133,7 @@ JNIEXPORT jstring OLM_UTILITY_FUNC_DEF(verifyEd25519SignatureJni)(JNIEnv *env, j
         if(result == olm_error()) {
             const char *errorMsgPtr = olm_utility_last_error(utilityPtr);
             errorMessageRetValue = env->NewStringUTF(errorMsgPtr);
-            LOGE("## verifyEd25519SignatureJni(): failure - session creation  Msg=%s",errorMsgPtr);
+            LOGE("## verifyEd25519SignatureJni(): failure - olm_ed25519_verify Msg=%s",errorMsgPtr);
         }
         else
         {