diff --git a/api/src/org/apache/cloudstack/api/command/user/vm/DeployVMCmd.java b/api/src/org/apache/cloudstack/api/command/user/vm/DeployVMCmd.java
index 87a68a6a2c3..a7d116f4d05 100755
--- a/api/src/org/apache/cloudstack/api/command/user/vm/DeployVMCmd.java
+++ b/api/src/org/apache/cloudstack/api/command/user/vm/DeployVMCmd.java
@@ -118,7 +118,7 @@ public class DeployVMCmd extends BaseAsyncCreateCustomIdCmd {
     @Parameter(name = ApiConstants.SIZE, type = CommandType.LONG, description = "the arbitrary size for the DATADISK volume. Mutually exclusive with diskOfferingId")
     private Long size;
 
-    @Parameter(name = ApiConstants.ROOT_DISK_SIZE, type = CommandType.LONG, since = "4.4", description = "Optional field to resize root disk on deploy. Only applies to template-based deployments. Analogous to details[0].rootdisksize")
+    @Parameter(name = ApiConstants.ROOT_DISK_SIZE, type = CommandType.LONG, description = "Optional field to resize root disk on deploy. Only applies to template-based deployments. Analogous to details[0].rootdisksize, which takes precedence over this parameter if both are provided")
     private Long rootdisksize;
 
     @Parameter(name = ApiConstants.GROUP, type = CommandType.STRING, description = "an optional group for the virtual machine")
@@ -219,7 +219,7 @@ public class DeployVMCmd extends BaseAsyncCreateCustomIdCmd {
                 }
             }
         }
-        if (rootdisksize != null) {
+        if (rootdisksize != null && !customparameterMap.containsKey("rootdisksize")) {
             customparameterMap.put("rootdisksize", rootdisksize.toString());
         }
         return customparameterMap;