diff --git a/src/main/java/de/mlessmann/certassist/openssl/OpenSSLCertificateCreator.java b/src/main/java/de/mlessmann/certassist/openssl/OpenSSLCertificateCreator.java
index 36d0bf1..cd41d56 100644
--- a/src/main/java/de/mlessmann/certassist/openssl/OpenSSLCertificateCreator.java
+++ b/src/main/java/de/mlessmann/certassist/openssl/OpenSSLCertificateCreator.java
@@ -42,8 +42,7 @@ public class OpenSSLCertificateCreator {
         [alt_names]
         """;
     private static final Pattern FINGERPRINT_EXTRACTOR = Pattern.compile(
-        "^(?<algo>[0-9a-z]+) Fingerprint=(?<finger>[a-z:A-Z0-9]+)",
-        Pattern.CASE_INSENSITIVE
+        "^(?<algo>[0-9a-zA-Z]+) (?i)Fingerprint(?-i)=(?<finger>[a-z:A-Z0-9]+)"
     );
 
     private final ExecutableResolver executableResolver;
@@ -293,7 +292,9 @@ public class OpenSSLCertificateCreator {
             Matcher matcher = FINGERPRINT_EXTRACTOR.matcher(output);
             if (!matcher.find()) {
                 log.debug(output);
-                throw new CommandLineOperationException("Unexpected output of fingerprint command. (See log for more details)");
+                throw new CommandLineOperationException(
+                    "Unexpected output of fingerprint command. (See log for more details)"
+                );
             }
             String algorithm = matcher.group("algo");
             String fingerprint = matcher.group("finger");