diff --git a/db/db_bench.cc b/db/db_bench.cc
index 623ba6a94..b99cac32f 100644
--- a/db/db_bench.cc
+++ b/db/db_bench.cc
@@ -1150,7 +1150,7 @@ int main(int argc, char** argv) {
     } else if (sscanf(argv[i], "--disable_wal=%d%c", &n, &junk) == 1 &&
         (n == 0 || n == 1)) {
       FLAGS_disable_wal = n;
-    } else if (sscanf(argv[i], "--hdfs=%s", &hdfsname) == 1) {
+    } else if (sscanf(argv[i], "--hdfs=%s", hdfsname) == 1) {
       FLAGS_env  = new leveldb::HdfsEnv(hdfsname);
     } else if (sscanf(argv[i], "--target_file_size_base=%d%c",
         &n, &junk) == 1) {
diff --git a/db/db_impl.cc b/db/db_impl.cc
index 18d51baca..abf17a0b7 100644
--- a/db/db_impl.cc
+++ b/db/db_impl.cc
@@ -160,7 +160,7 @@ DBImpl::DBImpl(const Options& options, const std::string& dbname)
 #endif
 
   char name[100];
-  Status st = env_->GetHostName(name, 100);
+  Status st = env_->GetHostName(name, 100L);
   if(st.ok()) {
     host_name_ = name;
   } else {
diff --git a/hdfs/env_hdfs.h b/hdfs/env_hdfs.h
index 4876b1dc3..4ec1b1f5d 100644
--- a/hdfs/env_hdfs.h
+++ b/hdfs/env_hdfs.h
@@ -122,7 +122,7 @@ class HdfsEnv : public Env {
     posixEnv->SleepForMicroseconds(micros);
   }
 
-  virtual Status GetHostName(char* name, uint len) {
+  virtual Status GetHostName(char* name, uint64_t len) {
     return posixEnv->GetHostName(name, len);
   }
 
@@ -262,7 +262,7 @@ class HdfsEnv : public Env {
 
   virtual void SleepForMicroseconds(int micros) {}
 
-  virtual Status GetHostName(char* name, uint len) {return notsup;}
+  virtual Status GetHostName(char* name, uint64_t len) {return notsup;}
 
   virtual Status GetCurrentTime(int64_t* unix_time) {return notsup;}
 
diff --git a/include/leveldb/env.h b/include/leveldb/env.h
index 2d045cc1d..a0e443af4 100644
--- a/include/leveldb/env.h
+++ b/include/leveldb/env.h
@@ -146,7 +146,7 @@ class Env {
   virtual void SleepForMicroseconds(int micros) = 0;
 
   // Get the current host name.
-  virtual Status GetHostName(char* name, uint len) = 0;
+  virtual Status GetHostName(char* name, uint64_t len) = 0;
 
   // Get the number of seconds since the Epoch, 1970-01-01 00:00:00 (UTC).
   virtual Status GetCurrentTime(int64_t* unix_time) = 0;
@@ -334,7 +334,7 @@ class EnvWrapper : public Env {
   void SleepForMicroseconds(int micros) {
     target_->SleepForMicroseconds(micros);
   }
-  Status GetHostName(char* name, uint len) {
+  Status GetHostName(char* name, uint64_t len) {
     return target_->GetHostName(name, len);
   }
   Status GetCurrentTime(int64_t* unix_time) {
diff --git a/tools/manifest_dump.cc b/tools/manifest_dump.cc
index 3268f1053..d8b0a9e0c 100644
--- a/tools/manifest_dump.cc
+++ b/tools/manifest_dump.cc
@@ -37,7 +37,7 @@ int main(int argc, char** argv) {
     if ((n = param.find("--file=")) != std::string::npos) {
       manifestfile = param.substr(strlen("--file="));
       foundfile = 1;
-    } else if (sscanf(argv[i], "--verbose=%d%c", &n, &junk) == 1 &&
+    } else if (sscanf(argv[i], "--verbose=%ld%c", &n, &junk) == 1 &&
         (n == 0 || n == 1)) {
       verbose = n;
     }
diff --git a/util/env_posix.cc b/util/env_posix.cc
index ee294e472..439d215db 100644
--- a/util/env_posix.cc
+++ b/util/env_posix.cc
@@ -553,7 +553,7 @@ class PosixEnv : public Env {
     usleep(micros);
   }
 
-  virtual Status GetHostName(char* name, uint len) {
+  virtual Status GetHostName(char* name, uint64_t len) {
     int ret = gethostname(name, len);
     if (ret < 0) {
       if (errno == EFAULT || errno == EINVAL)