diff --git a/src/utils.cpp b/src/utils.cpp
index 6c288002b9..bd553d974a 100644
--- a/src/utils.cpp
+++ b/src/utils.cpp
@@ -353,7 +353,7 @@ std::string utils::check_packages_for_style(const std::string &style, const std:
    called by various commands to check validity of their arguments
 ------------------------------------------------------------------------- */
 
-bool utils::logical(const char *file, int line, const char *str, bool do_abort, LAMMPS *lmp)
+int utils::logical(const char *file, int line, const char *str, bool do_abort, LAMMPS *lmp)
 {
   int n = 0;
 
@@ -372,11 +372,11 @@ bool utils::logical(const char *file, int line, const char *str, bool do_abort,
   if (has_utf8(buf)) buf = utf8_subst(buf);
   std::transform(buf.begin(), buf.end(), buf.begin(), tolower);
 
-  bool rv = false;
+  int rv = 0;
   if ((buf == "yes") || (buf == "on") || (buf == "true") || (buf == "1")) {
-    rv = true;
+    rv = 1;
   } else if ((buf == "no") || (buf == "off") || (buf == "false") || (buf == "0")) {
-    rv = false;
+    rv = 0;
   } else {
     std::string msg("Expected boolean parameter instead of '");
     msg += buf + "' in input script or data file";
diff --git a/src/utils.h b/src/utils.h
index 65a1462716..53077a3d5a 100644
--- a/src/utils.h
+++ b/src/utils.h
@@ -162,16 +162,16 @@ namespace utils {
 
   /*! Convert a string to a boolean while checking whether it is a valid boolean term.
    *  Valid terms are 'yes', 'no', 'true', 'false', 'on', 'off', '1', '0'. Capilatization
-   *  will be ignored (thus 'yEs' or 'nO' are valid, 'yay' or 'nay' are not).
+   *  will be ignored (thus 'yEs' or 'nO' are valid, 'yeah' or 'nope' are not).
    *
    *  \param file     name of source file for error message
    *  \param line     line number in source file for error message
    *  \param str      string to be converted to logical
    *  \param do_abort determines whether to call Error::one() or Error::all()
    *  \param lmp      pointer to top-level LAMMPS class instance
-   *  \return         boolean */
+   *  \return         1 if string resolves to "true", otherwise 0 */
 
-  bool logical(const char *file, int line, const char *str, bool do_abort, LAMMPS *lmp);
+  int logical(const char *file, int line, const char *str, bool do_abort, LAMMPS *lmp);
 
   /*! Convert a string to a floating point number while checking
    *  if it is a valid floating point or integer number
diff --git a/unittest/formats/test_input_convert.cpp b/unittest/formats/test_input_convert.cpp
index ea7712b36c..020e86a65b 100644
--- a/unittest/formats/test_input_convert.cpp
+++ b/unittest/formats/test_input_convert.cpp
@@ -40,26 +40,26 @@ protected:
 
 TEST_F(InputConvertTest, logical)
 {
-    EXPECT_TRUE(utils::logical(FLERR, "yes", false, lmp));
-    EXPECT_TRUE(utils::logical(FLERR, "Yes", false, lmp));
-    EXPECT_TRUE(utils::logical(FLERR, "YES", false, lmp));
-    EXPECT_TRUE(utils::logical(FLERR, "yEs", false, lmp));
-    EXPECT_TRUE(utils::logical(FLERR, "true", false, lmp));
-    EXPECT_TRUE(utils::logical(FLERR, "True", false, lmp));
-    EXPECT_TRUE(utils::logical(FLERR, "TRUE", false, lmp));
-    EXPECT_TRUE(utils::logical(FLERR, "on", false, lmp));
-    EXPECT_TRUE(utils::logical(FLERR, "On", false, lmp));
-    EXPECT_TRUE(utils::logical(FLERR, "ON", false, lmp));
-    EXPECT_TRUE(utils::logical(FLERR, "1", false, lmp));
-    EXPECT_FALSE(utils::logical(FLERR, "no", false, lmp));
-    EXPECT_FALSE(utils::logical(FLERR, "No", false, lmp));
-    EXPECT_FALSE(utils::logical(FLERR, "NO", false, lmp));
-    EXPECT_FALSE(utils::logical(FLERR, "nO", false, lmp));
-    EXPECT_FALSE(utils::logical(FLERR, "off", false, lmp));
-    EXPECT_FALSE(utils::logical(FLERR, "Off", false, lmp));
-    EXPECT_FALSE(utils::logical(FLERR, "OFF", false, lmp));
-    EXPECT_FALSE(utils::logical(FLERR, "OfF", false, lmp));
-    EXPECT_FALSE(utils::logical(FLERR, "0", false, lmp));
+    EXPECT_EQ(utils::logical(FLERR, "yes", false, lmp), 1);
+    EXPECT_EQ(utils::logical(FLERR, "Yes", false, lmp), 1);
+    EXPECT_EQ(utils::logical(FLERR, "YES", false, lmp), 1);
+    EXPECT_EQ(utils::logical(FLERR, "yEs", false, lmp), 1);
+    EXPECT_EQ(utils::logical(FLERR, "true", false, lmp), 1);
+    EXPECT_EQ(utils::logical(FLERR, "True", false, lmp), 1);
+    EXPECT_EQ(utils::logical(FLERR, "TRUE", false, lmp), 1);
+    EXPECT_EQ(utils::logical(FLERR, "on", false, lmp), 1);
+    EXPECT_EQ(utils::logical(FLERR, "On", false, lmp), 1);
+    EXPECT_EQ(utils::logical(FLERR, "ON", false, lmp), 1);
+    EXPECT_EQ(utils::logical(FLERR, "1", false, lmp), 1);
+    EXPECT_EQ(utils::logical(FLERR, "no", false, lmp), 0);
+    EXPECT_EQ(utils::logical(FLERR, "No", false, lmp), 0);
+    EXPECT_EQ(utils::logical(FLERR, "NO", false, lmp), 0);
+    EXPECT_EQ(utils::logical(FLERR, "nO", false, lmp), 0);
+    EXPECT_EQ(utils::logical(FLERR, "off", false, lmp), 0);
+    EXPECT_EQ(utils::logical(FLERR, "Off", false, lmp), 0);
+    EXPECT_EQ(utils::logical(FLERR, "OFF", false, lmp), 0);
+    EXPECT_EQ(utils::logical(FLERR, "OfF", false, lmp), 0);
+    EXPECT_EQ(utils::logical(FLERR, "0", false, lmp), 0);
 
     TEST_FAILURE(".*ERROR: Expected boolean parameter instead of.*",
                  utils::logical(FLERR, "yay", false, lmp););
@@ -84,8 +84,7 @@ TEST_F(InputConvertTest, numeric)
 
     TEST_FAILURE(".*ERROR: Expected floating point.*", utils::numeric(FLERR, "yay", false, lmp););
     TEST_FAILURE(".*ERROR: Expected floating point.*", utils::numeric(FLERR, "", false, lmp););
-    TEST_FAILURE(".*ERROR: Expected floating point.*",
-                 utils::numeric(FLERR, nullptr, false, lmp););
+    TEST_FAILURE(".*ERROR: Expected floating point.*", utils::numeric(FLERR, nullptr, false, lmp););
     TEST_FAILURE(".*ERROR: Expected floating point.*",
                  utils::numeric(FLERR, "2.56D+3", false, lmp););
 }