diff --git a/src/main/io/DataFileReader.java b/src/main/io/DataFileReader.java
index 2f49a5c..ad9585c 100644
--- a/src/main/io/DataFileReader.java
+++ b/src/main/io/DataFileReader.java
@@ -32,8 +32,13 @@ public void close() {
     private String nextLine() {
         String nextLine = fileScanner.nextLine().trim();
 
-        if (commentStr != null)
-            nextLine = nextLine.split(commentStr)[0].trim();
+        if (commentStr != null) {
+            if (nextLine.equals(commentStr)) {
+                nextLine = "";
+            } else {
+                nextLine = nextLine.split(commentStr)[0].trim();
+            }
+        }
 
         // Since blank lines are ignored
         if (nextLine.length() == 0)
diff --git a/test/main/io/DataFileReaderTest.java b/test/main/io/DataFileReaderTest.java
index 1feb314..6a97cd2 100644
--- a/test/main/io/DataFileReaderTest.java
+++ b/test/main/io/DataFileReaderTest.java
@@ -18,26 +18,28 @@ public void readWithComments() throws IOException {
         File tempFile = new File("test/test_data/dataFileTest.cfd");
 
         try (FileWriter writer = new FileWriter(tempFile)) {
-            String textWithComments = "% Comment line\n" +
-                    "int_param1=56\n" +
-                    "IntParam2 =    85\n" +
-                    "DoubleParam1 = 2452 % This a double param\n" +
-                    "str1 = Just a plain line\n" +
-                    "987 34 76\n" +
-                    "45 72 25 98 41 23 14 57 92 12    % int array\n" +
-                    "line=empty";
+            String textWithComments = """
+                    % Comment line
+                    int_param1=56
+                    IntParam2 =    85
+                    DoubleParam1 = 2452 % This a double param
+                    str1 = Just a plain line
+                    987 34 76
+                    45 72 25 98 41 23 14 57 92 12    % int array
+                    line=empty""";
             writer.write(textWithComments);
         }
-        DataFileReader fileReader = new DataFileReader(tempFile, "%");
+        try (DataFileReader fileReader = new DataFileReader(tempFile, "%")) {
 
-        assertEquals(56, fileReader.readIntParameter("int_param1"));
-        assertEquals(85, fileReader.readIntParameter("IntParam2"));
-        assertEquals(2452, fileReader.readDoubleParameter("DoubleParam1"), 1e-15);
-        assertEquals("Just a plain line", fileReader.readParameter("str1"));
-        assertEquals(0, new Point(987, 34, 76).distance(fileReader.readXYZ()), 1e-15);
-        assertArrayEquals(new int[]{45, 72, 25, 98, 41, 23, 14, 57, 92, 12}, fileReader.readIntArray());
+            assertEquals(56, fileReader.readIntParameter("int_param1"));
+            assertEquals(85, fileReader.readIntParameter("IntParam2"));
+            assertEquals(2452, fileReader.readDoubleParameter("DoubleParam1"), 1e-15);
+            assertEquals("Just a plain line", fileReader.readParameter("str1"));
+            assertEquals(0, new Point(987, 34, 76).distance(fileReader.readXYZ()), 1e-15);
+            assertArrayEquals(new int[]{45, 72, 25, 98, 41, 23, 14, 57, 92, 12}, fileReader.readIntArray());
 
-        assertThrows(IllegalArgumentException.class, () -> fileReader.readParameter("Dummy")); // line=empty
+            assertThrows(IllegalArgumentException.class, () -> fileReader.readParameter("Dummy")); // line=empty
+        }
 
         if (!tempFile.delete()) System.out.println("Unable to delete temporary file: " + tempFile);
     }
@@ -47,22 +49,54 @@ public void readWithoutComments() throws IOException {
         File tempFile = new File("test/test_data/dataFileTest.cfd");
 
         try (FileWriter writer = new FileWriter(tempFile)) {
-            String textWithoutComments = "int_param1=56\n" +
-                    "IntParam2 =    85\n" +
-                    "DoubleParam1 = 2452 \n" +
-                    "str1 = Just a plain line\n" +
-                    "987 34 76\n" +
-                    "45 72 25 98 41 23 14 57 92 12\n";
+            String textWithoutComments = """
+                    int_param1=56
+                    IntParam2 =    85
+                    DoubleParam1 = 2452\s
+                    str1 = Just a plain line
+                    987 34 76
+                    45 72 25 98 41 23 14 57 92 12
+                    """;
             writer.write(textWithoutComments);
         }
-        DataFileReader fileReader = new DataFileReader(tempFile);
-
-        assertEquals(56, fileReader.readIntParameter("int_param1"));
-        assertEquals(85, fileReader.readIntParameter("IntParam2"));
-        assertEquals(2452, fileReader.readDoubleParameter("DoubleParam1"), 1e-15);
-        assertEquals("Just a plain line", fileReader.readParameter("str1"));
-        assertEquals(0, new Point(987, 34, 76).distance(fileReader.readXYZ()), 1e-15);
-        assertArrayEquals(new int[]{45, 72, 25, 98, 41, 23, 14, 57, 92, 12}, fileReader.readIntArray());
+        try (DataFileReader fileReader = new DataFileReader(tempFile)) {
+
+            assertEquals(56, fileReader.readIntParameter("int_param1"));
+            assertEquals(85, fileReader.readIntParameter("IntParam2"));
+            assertEquals(2452, fileReader.readDoubleParameter("DoubleParam1"), 1e-15);
+            assertEquals("Just a plain line", fileReader.readParameter("str1"));
+            assertEquals(0, new Point(987, 34, 76).distance(fileReader.readXYZ()), 1e-15);
+            assertArrayEquals(new int[]{45, 72, 25, 98, 41, 23, 14, 57, 92, 12}, fileReader.readIntArray());
+        }
+
+        if (!tempFile.delete()) System.out.println("Unable to delete temporary file: " + tempFile);
+    }
+
+    @Test
+    public void file_with_only_comment_on_a_line() throws IOException {
+        File tempFile = new File("test/test_data/dataFileTest.cfd");
+
+        try (FileWriter writer = new FileWriter(tempFile)) {
+            String textWithoutComments = """
+                    %
+                    int_param1=56
+                    IntParam2 =    85
+                    DoubleParam1= 2452\s
+                    str1 = Just a plain line
+                    987 34 76
+                    45 72 25 98 41 23 14 57 92 12
+                    """;
+            writer.write(textWithoutComments);
+        }
+        try (DataFileReader fileReader = new DataFileReader(tempFile, "%")) {
+
+            assertEquals(56, fileReader.readIntParameter("int_param1"));
+            assertEquals(85, fileReader.readIntParameter("IntParam2"));
+            assertEquals(2452, fileReader.readDoubleParameter("DoubleParam1"), 1e-15);
+            assertEquals("Just a plain line", fileReader.readParameter("str1"));
+            assertEquals(0, new Point(987, 34, 76).distance(fileReader.readXYZ()), 1e-15);
+            assertArrayEquals(new int[]{45, 72, 25, 98, 41, 23, 14, 57, 92, 12}, fileReader.readIntArray());
+        }
 
         if (!tempFile.delete()) System.out.println("Unable to delete temporary file: " + tempFile);
     }