diff --git a/pgpainless-sop/src/main/kotlin/org/pgpainless/sop/ArmorImpl.kt b/pgpainless-sop/src/main/kotlin/org/pgpainless/sop/ArmorImpl.kt
index 40ac811d..2a5dd6e7 100644
--- a/pgpainless-sop/src/main/kotlin/org/pgpainless/sop/ArmorImpl.kt
+++ b/pgpainless-sop/src/main/kotlin/org/pgpainless/sop/ArmorImpl.kt
@@ -14,6 +14,7 @@ import org.pgpainless.util.ArmoredOutputStreamFactory
 import sop.Ready
 import sop.exception.SOPGPException
 import sop.operation.Armor
+import java.io.IOException
 
 /** Implementation of the `armor` operation using PGPainless. */
 class ArmorImpl : Armor {
@@ -26,8 +27,14 @@ class ArmorImpl : Armor {
                 val bufferedOutputStream = BufferedOutputStream(outputStream)
 
                 // Determine the nature of the given data
-                val openPgpIn = OpenPgpInputStream(data)
-                openPgpIn.reset()
+                val openPgpIn = OpenPgpInputStream(data, false).apply {
+                    try {
+                        inspectBuffer()
+                    } catch (e: IOException) {
+                        // ignore
+                    }
+                    reset()
+                }
 
                 if (openPgpIn.isAsciiArmored) {
                     // armoring already-armored data is an idempotent operation