diff --git a/backend/Dockerfile b/backend/Dockerfile
index 6225a4cd7..c09e5aaf8 100644
--- a/backend/Dockerfile
+++ b/backend/Dockerfile
@@ -98,10 +98,18 @@ COPY --from=build ${DOCKER_WORKDIR}/../database/build ../database/build
 # We also copy the node_modules express and serve-static for the run script
 COPY --from=build ${DOCKER_WORKDIR}/node_modules ./node_modules
 COPY --from=build ${DOCKER_WORKDIR}/../database/node_modules ../database/node_modules
+
 # Copy static files
 # COPY --from=build ${DOCKER_WORKDIR}/public ./public
 # Copy package.json for script definitions (lock file should not be needed)
 COPY --from=build ${DOCKER_WORKDIR}/package.json ./package.json
+# Copy tsconfig.json to provide alias path definitions
+COPY --from=build ${DOCKER_WORKDIR}/tsconfig.json ./tsconfig.json
+# Copy log4js-config.json to provide log configuration
+COPY --from=build ${DOCKER_WORKDIR}/log4js-config.json ./log4js-config.json
+# Copy memonic type since its referenced in the sources
+# TODO: remove
+COPY --from=build ${DOCKER_WORKDIR}/src/config/mnemonic.uncompressed_buffer13116.txt ./src/config/mnemonic.uncompressed_buffer13116.txt
 # Copy run scripts run/
 # COPY --from=build ${DOCKER_WORKDIR}/run ./run
 
diff --git a/backend/src/graphql/resolver/TransactionResolver.test.ts b/backend/src/graphql/resolver/TransactionResolver.test.ts
index f4315d359..1d4fe5708 100644
--- a/backend/src/graphql/resolver/TransactionResolver.test.ts
+++ b/backend/src/graphql/resolver/TransactionResolver.test.ts
@@ -291,7 +291,6 @@ describe('send coins', () => {
       await cleanDB()
     })
 
-    /*
     describe('trying to send negative amount', () => {
       it('throws an error', async () => {
         expect(
@@ -305,18 +304,15 @@ describe('send coins', () => {
           }),
         ).toEqual(
           expect.objectContaining({
-            errors: [new GraphQLError(`user hasn't enough GDD or amount is < 0`)],
+            errors: [new GraphQLError(`Amount to send must be positive`)],
           }),
         )
       })
 
       it('logs the error thrown', () => {
-        expect(logger.error).toBeCalledWith(
-          `user hasn't enough GDD or amount is < 0 : balance=null`,
-        )
+        expect(logger.error).toBeCalledWith(`Amount to send must be positive`)
       })
     })
-    */
 
     describe('good transaction', () => {
       it('sends the coins', async () => {
diff --git a/backend/src/graphql/resolver/TransactionResolver.ts b/backend/src/graphql/resolver/TransactionResolver.ts
index 594039cfd..3dbd4afb9 100644
--- a/backend/src/graphql/resolver/TransactionResolver.ts
+++ b/backend/src/graphql/resolver/TransactionResolver.ts
@@ -314,6 +314,10 @@ export class TransactionResolver {
     @Ctx() context: Context,
   ): Promise<boolean> {
     logger.info(`sendCoins(email=${email}, amount=${amount}, memo=${memo})`)
+    if (amount.lte(0)) {
+      logger.error(`Amount to send must be positive`)
+      throw new Error('Amount to send must be positive')
+    }
 
     // TODO this is subject to replay attacks
     const senderUser = getUser(context)
@@ -324,22 +328,7 @@ export class TransactionResolver {
 
     // validate recipient user
     const recipientUser = await findUserByEmail(email)
-    /*
-    const emailContact = await UserContact.findOne({ email }, { withDeleted: true })
-    if (!emailContact) {
-      logger.error(`Could not find UserContact with email: ${email}`)
-      throw new Error(`Could not find UserContact with email: ${email}`)
-    }
-    */
-    // const recipientUser = await dbUser.findOne({ id: emailContact.userId })
 
-    /* Code inside this if statement is unreachable (useless by so), 
-    in findUserByEmail() an error is already thrown if the user is not found
-    */
-    if (!recipientUser) {
-      logger.error(`unknown recipient to UserContact: email=${email}`)
-      throw new Error('unknown recipient')
-    }
     if (recipientUser.deletedAt) {
       logger.error(`The recipient account was deleted: recipientUser=${recipientUser}`)
       throw new Error('The recipient account was deleted')
diff --git a/backend/src/graphql/resolver/util/creations.test.ts b/backend/src/graphql/resolver/util/creations.test.ts
index 8d747e989..6be317e16 100644
--- a/backend/src/graphql/resolver/util/creations.test.ts
+++ b/backend/src/graphql/resolver/util/creations.test.ts
@@ -170,8 +170,11 @@ describe('util/creation', () => {
         const targetDate = new Date(now.getFullYear(), now.getMonth() + 1, 0, 23, 0, 0)
 
         beforeAll(() => {
+          const halfMsToRun = (targetDate.getTime() - now.getTime()) / 2
           jest.useFakeTimers()
-          setTimeout(jest.fn(), targetDate.getTime() - now.getTime())
+          setTimeout(jest.fn(), halfMsToRun)
+          jest.runAllTimers()
+          setTimeout(jest.fn(), halfMsToRun)
           jest.runAllTimers()
         })
 
@@ -225,8 +228,10 @@ describe('util/creation', () => {
           })
 
           it('has the clock set correctly', () => {
+            const targetMonth = nextMonthTargetDate.getMonth() + 1
+            const targetMonthString = (targetMonth < 10 ? '0' : '') + String(targetMonth)
             expect(new Date().toISOString()).toContain(
-              `${nextMonthTargetDate.getFullYear()}-${nextMonthTargetDate.getMonth() + 1}-01T01:`,
+              `${nextMonthTargetDate.getFullYear()}-${targetMonthString}-01T01:`,
             )
           })