diff --git a/src/impl/list_ports/list_ports_linux.cc b/src/impl/list_ports/list_ports_linux.cc
index db2afb2c..b6f1f661 100644
--- a/src/impl/list_ports/list_ports_linux.cc
+++ b/src/impl/list_ports/list_ports_linux.cc
@@ -63,7 +63,7 @@ glob(const vector<string>& patterns)
         glob_retval = glob(iter->c_str(), GLOB_APPEND, NULL, &glob_results);
     }
 
-    for(int path_index = 0; path_index < glob_results.gl_pathc; path_index++)
+    for(size_t path_index = 0; path_index < glob_results.gl_pathc; path_index++)
     {
         paths_found.push_back(glob_results.gl_pathv[path_index]);
     }
@@ -243,7 +243,7 @@ format(const char* format, ...)
         {
             done = true;
         }
-        else if( return_value >= buffer_size_bytes )
+        else if( return_value >= static_cast<int>(buffer_size_bytes) )
         {
             // Realloc and try again.