diff --git a/.travis.yml b/.travis.yml
index 49f5300..274dc83 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,7 +1,6 @@
 language: php
 
 php:
-  - 7.1.3
   - 7.2
   - 7.3
 
diff --git a/composer.json b/composer.json
index 8ae66a3..6b09cc6 100755
--- a/composer.json
+++ b/composer.json
@@ -17,11 +17,11 @@
 		"psr-4": { "Ang3\\Component\\Serializer\\Encoder\\Tests\\": "tests/" }
 	},
     "require": {
-    	"php": "^7.1",
+    	"php": "^7.2",
 		"phpoffice/phpspreadsheet": "^1.9",
 		"symfony/serializer": "^4.1",
-		"symfony/filesystem": "^3.0 || ^4.0",
-		"symfony/property-access": "^3.0 || ^4.0"
+		"symfony/filesystem": "^4.0",
+		"symfony/property-access": "^4.0"
     },
     "require-dev": {
 		"symfony/phpunit-bridge": "^4.2.7 || ^4.3 || ^5.0 || ^6.0",
diff --git a/composer.lock b/composer.lock
index f9e881d..285f153 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "80dd56b94d0243254264bb3559c6646f",
+    "content-hash": "271f5fd8791ccc69ac67024be4884448",
     "packages": [
         {
             "name": "markbaker/complex",
@@ -2254,7 +2254,7 @@
     "prefer-stable": false,
     "prefer-lowest": false,
     "platform": {
-        "php": "^7.1"
+        "php": "^7.2"
     },
     "platform-dev": []
 }