diff --git a/core/translate/index.rs b/core/translate/index.rs
index 1100aa27e..b79d9d834 100644
--- a/core/translate/index.rs
+++ b/core/translate/index.rs
@@ -353,6 +353,15 @@ pub fn translate_drop_index(
             )));
         }
     }
+    // Return an error if the index is associated with a unique or primary key constraint.
+    if let Some(idx) = maybe_index {
+        if idx.unique {
+            return Err(crate::error::LimboError::InvalidArgument(
+                "index associated with UNIQUE or PRIMARY KEY constraint cannot be dropped"
+                    .to_string(),
+            ));
+        }
+    }
 
     let cdc_table = prepare_cdc_if_necessary(&mut program, schema, SQLITE_TABLEID)?;
 
diff --git a/testing/drop_index.test b/testing/drop_index.test
index 4edbfc2bc..7ddc21a45 100755
--- a/testing/drop_index.test
+++ b/testing/drop_index.test
@@ -44,3 +44,15 @@ do_execsql_test_on_specific_db {:memory:} drop-index-after-ops-1 {
     DROP INDEX t_idx6;
     SELECT count(*) FROM sqlite_schema WHERE type='index' AND name='t_idx6';
 } {0}
+
+# Test dropping of indices associated with unique or primary contraint indices produces an error
+do_execsql_test_in_memory_error_content  drop-index-primary-key-index {
+    CREATE TABLE t15a (id TEXT PRIMARY KEY );
+    DROP INDEX sqlite_autoindex_t15a_1;
+} {"index associated with UNIQUE or PRIMARY KEY constraint cannot be dropped"}
+
+
+do_execsql_test_in_memory_error_content drop-index-unique-index {
+    CREATE TABLE t15b (id INT UNIQUE );
+    DROP INDEX sqlite_autoindex_t15b_1;
+} {"index associated with UNIQUE or PRIMARY KEY constraint cannot be dropped"}
\ No newline at end of file
diff --git a/testing/tester.tcl b/testing/tester.tcl
index 98d06f26f..6fbfa2dd5 100644
--- a/testing/tester.tcl
+++ b/testing/tester.tcl
@@ -191,9 +191,13 @@ proc run_test_expecting_error_content {sqlite_exec db_name sql expected_error_te
         exit 1
     }
 
+    # Remove box-drawing characters, multiplication signs, and other non-ASCII junk
+    set cleaned_result [regsub -all {[\u2500-\u257F\u00D7]} $result ""]
+    #TODO any other possible cleanups?
+    
     # Normalize both the actual and expected error messages
     # Remove all whitespace, newlines, and special characters for comparison
-    set normalized_actual [regsub -all {[[:space:]]|[[:punct:]]} $result ""]
+    set normalized_actual [regsub -all {[[:space:]]|[[:punct:]]} $cleaned_result ""]
     set normalized_expected [regsub -all {[[:space:]]|[[:punct:]]} $expected_error_text ""]
 
     # Convert to lowercase for case-insensitive comparison