diff --git a/lib/saxes.js b/lib/saxes.js
index f6516011..17e85b83 100644
--- a/lib/saxes.js
+++ b/lib/saxes.js
@@ -543,6 +543,13 @@ class SAXParser {
           this.piTarget = this.piBody = "";
           this.state = S_TEXT;
         }
+        else if (c === "?") {
+          // We ran into ?? as part of a processing instruction. We initially
+          // took the first ? as a sign that the PI was ending, but it is
+          // not. So we have to add it to the body but we take the new ? as a
+          // sign that the PI is ending.
+          this.piBody += "?";
+        }
         else {
           this.piBody += `?${c}`;
           this.state = S_PI_BODY;