diff --git a/src/smt/theory_str.cpp b/src/smt/theory_str.cpp
index 9f0975609..b2e0e70ba 100644
--- a/src/smt/theory_str.cpp
+++ b/src/smt/theory_str.cpp
@@ -32,7 +32,7 @@ theory_str::theory_str(ast_manager & m):
         /* Options */
         opt_AggressiveLengthTesting(false),
         opt_AggressiveValueTesting(false),
-        opt_AggressiveUnrollTesting(true),
+        opt_AggressiveUnrollTesting(false),
         opt_EagerStringConstantLengthAssertions(true),
         opt_VerifyFinalCheckProgress(true),
 		opt_LCMUnrollStep(2),