diff --git a/src/molecule.cpp b/src/molecule.cpp
index 8221a08b5f..cf9d995e2b 100644
--- a/src/molecule.cpp
+++ b/src/molecule.cpp
@@ -773,7 +773,7 @@ void Molecule::fragments(char *line)
 
       ValueTokenizer values(line);
 
-      if (values.count() > natoms+1)
+      if ((int)values.count() > natoms+1)
         error->one(FLERR,"Invalid atom ID in Fragments section of molecule file");
 
       fragmentnames[i] = values.next_string();
diff --git a/src/reader_native.cpp b/src/reader_native.cpp
index b329dd4f70..9b93c78000 100644
--- a/src/reader_native.cpp
+++ b/src/reader_native.cpp
@@ -320,7 +320,7 @@ void ReaderNative::read_atoms(int n, int nfield, double **fields)
     // tokenize the line
     std::vector<std::string> words = Tokenizer(line).as_vector();
 
-    if (words.size() < nwords) error->one(FLERR,"Insufficient columns in dump file");
+    if ((int)words.size() < nwords) error->one(FLERR,"Insufficient columns in dump file");
 
     // convert selected fields to floats