diff --git a/pom.xml b/pom.xml
index fb1d5310c2..d0b0c115a6 100644
--- a/pom.xml
+++ b/pom.xml
@@ -85,12 +85,11 @@
                 <dependencies>
                     <dependency>
                         <groupId>org.apache.maven.surefire</groupId>
-                        <artifactId>surefire-junit4</artifactId>
+                        <artifactId>surefire-testng</artifactId>
                         <version>${surefire-version}</version>
                     </dependency>
                 </dependencies>
                 <configuration>
-                    <testNGArtifactName>none:none</testNGArtifactName>
                     <argLine>-javaagent:${settings.localRepository}/org/jmockit/jmockit/${jmockit-version}/jmockit-${jmockit-version}.jar -XX:+IgnoreUnrecognizedVMOptions --add-opens=java.base/java.util=ALL-UNNAMED</argLine>
                 </configuration>
             </plugin>
diff --git a/src/main/java/io/swagger/codegen/v3/generators/DefaultCodegenConfig.java b/src/main/java/io/swagger/codegen/v3/generators/DefaultCodegenConfig.java
index a496894a08..93059b9f3f 100644
--- a/src/main/java/io/swagger/codegen/v3/generators/DefaultCodegenConfig.java
+++ b/src/main/java/io/swagger/codegen/v3/generators/DefaultCodegenConfig.java
@@ -1815,12 +1815,23 @@ protected void processPropertySchemaContainerTypes(CodegenProperty codegenProper
     }
 
     private void handleMinMaxValues(Schema propertySchema, CodegenProperty codegenProperty) {
-        if (propertySchema.getMinimum() != null) {
-            codegenProperty.minimum = String.valueOf(propertySchema.getMinimum().longValue());
-        }
-        if (propertySchema.getMaximum() != null) {
-            codegenProperty.maximum = String.valueOf(propertySchema.getMaximum().longValue());
-        }
+    	if (propertySchema.getMaximum() != null) {
+    		long maximumLongValue = propertySchema.getMaximum().longValue();
+    		if (maximumLongValue > Integer.MAX_VALUE || maximumLongValue < Integer.MIN_VALUE) {
+    			codegenProperty.maximum = String.valueOf(propertySchema.getMaximum().longValue()) + "L";
+    		} else {
+    			codegenProperty.maximum = String.valueOf(propertySchema.getMaximum().longValue());
+    		}
+    	}
+    	if (propertySchema.getMinimum() != null) {
+    		long minimumLongValue = propertySchema.getMinimum().longValue();
+    		if (minimumLongValue > Integer.MAX_VALUE || minimumLongValue < Integer.MIN_VALUE) {
+    			codegenProperty.minimum = String.valueOf(propertySchema.getMinimum().longValue()) + "L";
+    		} else {
+    			codegenProperty.minimum = String.valueOf(propertySchema.getMinimum().longValue());
+    		}
+    	}
+    	
         if (propertySchema.getExclusiveMinimum() != null) {
             codegenProperty.exclusiveMinimum = propertySchema.getExclusiveMinimum();
         }
@@ -2582,8 +2593,26 @@ public CodegenParameter fromParameter(Parameter parameter, Set<String> imports)
             // validation
             // handle maximum, minimum properly for int/long by removing the trailing ".0"
             if (parameterSchema instanceof IntegerSchema) {
-                codegenParameter.maximum = parameterSchema.getMaximum() == null ? null : String.valueOf(parameterSchema.getMaximum().longValue());
-                codegenParameter.minimum = parameterSchema.getMinimum() == null ? null : String.valueOf(parameterSchema.getMinimum().longValue());
+            	if (parameterSchema.getMaximum() == null) {
+            		codegenParameter.maximum = null;
+            	} else {
+            		long maximumLongValue = parameterSchema.getMaximum().longValue();
+            		if (maximumLongValue > Integer.MAX_VALUE || maximumLongValue < Integer.MIN_VALUE) {
+            			codegenParameter.maximum = String.valueOf(parameterSchema.getMaximum().longValue()) + "L";
+            		} else {
+            			codegenParameter.maximum = String.valueOf(parameterSchema.getMaximum().longValue());
+            		}
+            	}
+            	if (parameterSchema.getMinimum() == null) {
+            		codegenParameter.minimum = null;
+            	} else {
+            		long minimumLongValue = parameterSchema.getMinimum().longValue();
+            		if (minimumLongValue > Integer.MAX_VALUE || minimumLongValue < Integer.MIN_VALUE) {
+            			codegenParameter.minimum = String.valueOf(parameterSchema.getMinimum().longValue()) + "L";
+            		} else {
+            			codegenParameter.minimum = String.valueOf(parameterSchema.getMinimum().longValue());
+            		}
+            	}     	
             } else {
                 codegenParameter.maximum = parameterSchema.getMaximum() == null ? null : String.valueOf(parameterSchema.getMaximum());
                 codegenParameter.minimum = parameterSchema.getMinimum() == null ? null : String.valueOf(parameterSchema.getMinimum());
diff --git a/src/test/java/io/swagger/codegen/v3/generators/DefaultCodegenConfigTest.java b/src/test/java/io/swagger/codegen/v3/generators/DefaultCodegenConfigTest.java
index 0a9fdf4ba0..7ff33affea 100644
--- a/src/test/java/io/swagger/codegen/v3/generators/DefaultCodegenConfigTest.java
+++ b/src/test/java/io/swagger/codegen/v3/generators/DefaultCodegenConfigTest.java
@@ -91,7 +91,7 @@ public void testPutAdditionalProperties() throws Exception {
 
     @Test
     public void testNumberSchemaMinMax() {
-        Schema schema = new NumberSchema()
+        Schema<?> schema = new NumberSchema()
                 .minimum(BigDecimal.valueOf(50))
                 .maximum(BigDecimal.valueOf(1000));
 
@@ -101,6 +101,21 @@ public void testNumberSchemaMinMax() {
         Assert.assertEquals(codegenProperty.minimum, "50");
         Assert.assertEquals(codegenProperty.maximum, "1000");
     }
+    
+    @Test
+    public void testNumberSchemaMinMaxForLong() {
+        Schema<?> schema = new NumberSchema()
+                .minimum(BigDecimal.valueOf(50))
+                .maximum(BigDecimal.valueOf(Integer.MAX_VALUE + 1L));
+        
+        schema.setFormat("int64");
+
+        final DefaultCodegenConfig codegen = new P_DefaultCodegenConfig();
+        CodegenProperty codegenProperty = codegen.fromProperty("test", schema);
+
+        Assert.assertEquals(codegenProperty.minimum, "50");
+        Assert.assertEquals(codegenProperty.maximum, Integer.MAX_VALUE + 1L + "L");
+    }
 
     @Test
     public void testFromOperation_BodyParamsUnique() {