diff --git a/core/src/main/java/com/google/errorprone/bugpatterns/threadsafety/GuardedByUtils.java b/core/src/main/java/com/google/errorprone/bugpatterns/threadsafety/GuardedByUtils.java
index a1a089875a1..deb83e7674e 100644
--- a/core/src/main/java/com/google/errorprone/bugpatterns/threadsafety/GuardedByUtils.java
+++ b/core/src/main/java/com/google/errorprone/bugpatterns/threadsafety/GuardedByUtils.java
@@ -19,6 +19,7 @@
 import static com.google.common.collect.ImmutableSet.toImmutableSet;
 import static com.google.errorprone.util.ASTHelpers.getSymbol;
 import static com.google.errorprone.util.ASTHelpers.isStatic;
+import static com.google.errorprone.util.ErrorProneLog.deferredDiagnosticHandler;
 
 import com.google.common.collect.ImmutableSet;
 import com.google.errorprone.VisitorState;
@@ -31,6 +32,7 @@
 import com.sun.tools.javac.parser.ParserFactory;
 import com.sun.tools.javac.tree.JCTree;
 import com.sun.tools.javac.util.Context;
+import com.sun.tools.javac.util.Log;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Optional;
@@ -80,11 +82,15 @@ static JCTree.JCExpression parseString(String guardedByString, Context context)
                 /* keepDocComments= */ false,
                 /* keepEndPos= */ true,
                 /* keepLineMap= */ false);
+    Log log = Log.instance(context);
+    Log.DeferredDiagnosticHandler deferredDiagnosticHandler = deferredDiagnosticHandler(log);
     JCTree.JCExpression exp;
     try {
       exp = parser.parseExpression();
     } catch (RuntimeException e) {
       throw new IllegalGuardedBy(e.getMessage());
+    } finally {
+      log.popDiagnosticHandler(deferredDiagnosticHandler);
     }
     int len = (parser.getEndPos(exp) - exp.getStartPosition());
     if (len != guardedByString.length()) {
diff --git a/core/src/test/java/com/google/errorprone/bugpatterns/threadsafety/GuardedByCheckerTest.java b/core/src/test/java/com/google/errorprone/bugpatterns/threadsafety/GuardedByCheckerTest.java
index 52b0d37decd..5aa520090c8 100644
--- a/core/src/test/java/com/google/errorprone/bugpatterns/threadsafety/GuardedByCheckerTest.java
+++ b/core/src/test/java/com/google/errorprone/bugpatterns/threadsafety/GuardedByCheckerTest.java
@@ -2511,4 +2511,23 @@ public static void t(I other) {
             """)
         .doTest();
   }
+
+  @Test
+  public void parseError() {
+    compilationHelper
+        .addSourceLines(
+            "IllegalStartOfExpression.java",
+            """
+            package example;
+
+            import com.google.errorprone.annotations.concurrent.GuardedBy;
+
+            public class IllegalStartOfExpression {
+              @GuardedBy("itself (synchronized blocks)")
+              // BUG: Diagnostic contains: could not resolve
+              int field;
+            }
+            """)
+        .doTest();
+  }
 }