diff --git a/.travis.yml b/.travis.yml
index b83b02bf..fd8c5fb4 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,9 +1,9 @@
 language: go
 go:
-  - 1.4.2
+  - 1.10.x
 
 before_install:
-  # for g++4.8 and C++11
+  # for g++5 and C++11
   - sudo add-apt-repository -y ppa:ubuntu-toolchain-r/test
 
   # Set up go-ethereum
@@ -15,9 +15,9 @@ before_install:
   - echo $GOPATH
 
 install:
-  # need to explicitly request version 1.48 since by default we get 1.46 which does not work with C++11
-  - sudo apt-get install -qq --yes --force-yes g++-4.8
-  - sudo update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-4.8 50
-  - sudo apt-get install -qq wget cmake bash libboost-test1.48-dev libboost-system1.48-dev libboost-filesystem1.48-dev nodejs python-pip python-dev valgrind
+  # need to explicitly request version 1.55 since by default we get 1.46 which does not work with C++11
+  - sudo apt-get install -qq --yes --force-yes g++-5
+  - sudo update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-5 50
+  - sudo apt-get install -qq wget cmake bash libboost-test1.55-dev libboost-system1.55-dev libboost-filesystem1.55-dev nodejs python-pip python-dev valgrind
   - sudo pip install virtualenv -q
 script: "./test/test.sh"
diff --git a/ethash.go b/ethash.go
index 21c10c87..837a16c1 100644
--- a/ethash.go
+++ b/ethash.go
@@ -130,7 +130,7 @@ func (l *Light) Verify(block Block) bool {
 	// to prevent DOS attacks.
 	blockNum := block.NumberU64()
 	if blockNum >= epochLength*2048 {
-		log.Debug(fmt.Sprintf("block number %d too high, limit is %d", epochLength*2048))
+		log.Debug(fmt.Sprintf("block number %d too high, limit is %d", blockNum, epochLength*2048))
 		return false
 	}