diff --git a/contracts/zero-ex/scripts/rollback.ts b/contracts/zero-ex/scripts/rollback.ts
index 6d014fa88c..cc99f2d6ba 100644
--- a/contracts/zero-ex/scripts/rollback.ts
+++ b/contracts/zero-ex/scripts/rollback.ts
@@ -236,13 +236,16 @@ async function functionHistoryAsync(proxyFunctions: ProxyFunctionEntity[]): Prom
         name: 'fnSelector',
         message: 'Enter the selector or name of the function:',
         choices: [
-            ..._.flatMap(Object.entries(selectorToSignature), ([selector, signature]) => [
-                { title: selector, value: selector, description: signature },
-                { title: signature, value: selector, description: selector },
-            ]),
-            ...proxyFunctions
-                .filter(fn => !Object.keys(selectorToSignature).includes(fn.id))
-                .map(fn => ({ title: fn.id, value: fn.id, description: '(function signature not found)' })),
+            ...proxyFunctions.map(fn => ({
+                title: fn.id,
+                value: fn.id,
+                description: selectorToSignature[fn.id] || '(function signature not found)',
+            })),
+            ...proxyFunctions.map(fn => ({
+                title: selectorToSignature[fn.id] || '(function signature not found)',
+                value: fn.id,
+                description: fn.id,
+            })),
         ],
     });
     const functionEntity = proxyFunctions.find(fn => fn.id === fnSelector);
@@ -312,13 +315,17 @@ async function generateRollbackAsync(proxyFunctions: ProxyFunctionEntity[]): Pro
                     value: constants.NULL_ADDRESS,
                     description: 'Rolls back to address(0)',
                 },
-                {
-                    title: 'PREVIOUS',
-                    value: previousImpl,
-                    description: `${previousImpl} (${timestampToUTC(
-                        _.findLast(fullHistory, update => update.impl === previousImpl)!.timestamp,
-                    )})`,
-                },
+                ...(previousImpl !== constants.NULL_ADDRESS
+                    ? [
+                          {
+                              title: 'PREVIOUS',
+                              value: previousImpl,
+                              description: `${previousImpl} (${timestampToUTC(
+                                  _.findLast(fullHistory, update => update.impl === previousImpl)!.timestamp,
+                              )})`,
+                          },
+                      ]
+                    : []),
                 ...[...new Set(rollbackHistory)]
                     .filter(impl => impl !== constants.NULL_ADDRESS)
                     .map(impl => ({