diff --git a/packages/tools/src/alterPlan.ts b/packages/tools/src/alterPlan.ts
index 3e0a64c3..a74e3b8f 100644
--- a/packages/tools/src/alterPlan.ts
+++ b/packages/tools/src/alterPlan.ts
@@ -259,6 +259,18 @@ export class AlterPlan {
         ];
       }
 
+      if (op.operationType == 'changeConstraint') {
+        const opDrop: AlterOperation = {
+          operationType: 'dropConstraint',
+          oldObject: op.oldObject,
+        };
+        const opCreate: AlterOperation = {
+          operationType: 'createConstraint',
+          newObject: op.newObject,
+        };
+        return [opDrop, opCreate];
+      }
+
       return [op];
     });
 
diff --git a/packages/tools/src/diffTools.ts b/packages/tools/src/diffTools.ts
index 729e16ad..a9b2435b 100644
--- a/packages/tools/src/diffTools.ts
+++ b/packages/tools/src/diffTools.ts
@@ -1,6 +1,7 @@
-import { ColumnInfo, DatabaseInfo, EngineDriver, NamedObjectInfo, TableInfo } from 'dbgate-types';
+import { ColumnInfo, ConstraintInfo, DatabaseInfo, EngineDriver, NamedObjectInfo, TableInfo } from 'dbgate-types';
 import uuidv1 from 'uuid/v1';
 import { AlterPlan } from './alterPlan';
+import stableStringify from 'json-stable-stringify';
 
 type DbDiffSchemaMode = 'strict' | 'ignore' | 'ignoreImplicit';
 
@@ -178,6 +179,10 @@ export function testEqualColumns(
   return true;
 }
 
+function testEqualConstraints(a: ConstraintInfo, b: ConstraintInfo, opts: DbDiffOptions = {}) {
+  return stableStringify(a) == stableStringify(b);
+}
+
 export function testEqualTypes(a: ColumnInfo, b: ColumnInfo, opts: DbDiffOptions = {}) {
   if (a.dataType != b.dataType) {
     // opts.DiffLogger.Trace("Column {0}, {1}: different types: {2}; {3}", a, b, a.DataType, b.DataType);
@@ -210,6 +215,7 @@ function getTableConstraints(table: TableInfo) {
   if (table.primaryKey) res.push(table.primaryKey);
   if (table.foreignKeys) res.push(...table.foreignKeys);
   if (table.indexes) res.push(...table.indexes);
+  if (table.uniques) res.push(...table.uniques);
   if (table.checks) res.push(...table.checks);
   return res;
 }
@@ -265,6 +271,15 @@ function planAlterTable(plan: AlterPlan, oldTable: TableInfo, newTable: TableInf
       }
     });
 
+  constraintPairs
+    .filter(x => x[0] && x[1])
+    .forEach(x => {
+      if (!testEqualConstraints(x[0], x[1], opts)) {
+        // console.log('PLAN CHANGE COLUMN')
+        plan.changeConstraint(x[0], x[1]);
+      }
+    });
+
   constraintPairs.filter(x => x[0] == null).forEach(x => plan.createConstraint(x[1]));
 }