diff --git a/src/atom.cpp b/src/atom.cpp
index cf676a8b0d..b1f4190002 100644
--- a/src/atom.cpp
+++ b/src/atom.cpp
@@ -1834,8 +1834,8 @@ void Atom::set_mass(const char *file, int line, int /*narg*/, char **arg)
 {
   if (mass == nullptr) error->all(file,line, "Cannot set atom mass for atom style {}", atom_style);
 
-  if (!isdigit(arg[0][0]) && arg[0][0] != '*') {
-    std::string typestr(arg[0]);
+  std::string typestr = utils::trim(arg[0]);
+  if (!isdigit(typestr[0]) && typestr[0] != '*') {
     int itype = lmap->find(typestr,Atom::ATOM);
     if (itype == -1) error->all(file,line,"Invalid type for mass set");
     mass[itype] = utils::numeric(FLERR,arg[1],false,lmp);
diff --git a/src/input.cpp b/src/input.cpp
index f5ad023513..72465cd9a9 100644
--- a/src/input.cpp
+++ b/src/input.cpp
@@ -728,7 +728,7 @@ int Input::readtype(char *&str, int mode)
 
   int type,max,max2;
   char typechar[256];
-  std::string labelstr(str);
+  std::string labelstr = utils::trim(str);
 
   type = atom->lmap->find(labelstr,mode);
   if (type == -1) error->all(FLERR,fmt::format("Invalid type {}",str));
diff --git a/src/label_map.cpp b/src/label_map.cpp
index 4aeb4f29a1..e95780135a 100644
--- a/src/label_map.cpp
+++ b/src/label_map.cpp
@@ -137,7 +137,7 @@ void LabelMap::modify_lmap(int narg, char **arg)
     int itype = utils::inumeric(FLERR, arg[iarg++], false, lmp);
     if ((itype < 1) || (itype > ntypes))
       error->all(FLERR, "Labelmap {} type {} must be within 1-{}", tlabel, itype, ntypes);
-    std::string slabel(arg[iarg++]);
+    std::string slabel = utils::trim(arg[iarg++]);
     if (isdigit(slabel[0]) || (slabel[0] == '#') || (slabel[0] == '*'))
       error->all(FLERR, "Label {} for {} type {} must not start with a number, a '#', or a '*'",
                  slabel, tlabel, itype);
diff --git a/unittest/commands/test_labelmap.cpp b/unittest/commands/test_labelmap.cpp
index 15344b45bb..bd4224864a 100644
--- a/unittest/commands/test_labelmap.cpp
+++ b/unittest/commands/test_labelmap.cpp
@@ -153,6 +153,16 @@ TEST_F(SetTest, NoBoxAtoms)
     ASSERT_FALSE(atom->lmap->is_complete(Atom::ATOM));
     ASSERT_EQ(atom->lmap->find("C1", Atom::ATOM), 3);
     ASSERT_EQ(atom->lmap->find("N2", Atom::ATOM), 2);
+
+    BEGIN_HIDE_OUTPUT();
+    command("labelmap clear");
+    command("labelmap atom 1 \"C1'\" 2 'C2\"' 3 \"\"\"C1'-C2\" \"\"\" 4 \"\"\" C2\"-C1'\"\"\"");
+    END_HIDE_OUTPUT();
+    ASSERT_TRUE(atom->lmap->is_complete(Atom::ATOM));
+    ASSERT_EQ(atom->lmap->find("C1'", Atom::ATOM), 1);
+    ASSERT_EQ(atom->lmap->find("C2\"", Atom::ATOM), 2);
+    ASSERT_EQ(atom->lmap->find("C1'-C2\"", Atom::ATOM), 3);
+    ASSERT_EQ(atom->lmap->find("C2\"-C1'", Atom::ATOM), 4);
 }
 
 } // namespace LAMMPS_NS