diff --git a/fprettify/__init__.py b/fprettify/__init__.py
index d6450a3..6a07edf 100644
--- a/fprettify/__init__.py
+++ b/fprettify/__init__.py
@@ -899,6 +899,8 @@ def replace_relational_single_fline(f_line, cstyle):
     .ne.  <-->  /=
     """
 
+    # keep track of whether the line may be affected
+    line_affected = False
     new_line = f_line
 
     # only act on lines that do contain a relation
@@ -942,8 +944,25 @@ def replace_relational_single_fline(f_line, cstyle):
             line_parts[pos] = part
 
         new_line = ''.join(line_parts)
+        line_affected = True
 
-    return new_line
+    return new_line, line_affected
+
+
+def replace_relational_lines(lines, cstyle):
+    """
+    format a list of lines - replaces scalar relational
+    operators in logical expressions to either Fortran or C-style
+    by calling original function for single line.
+    """
+
+    new_lines = []
+
+    for f_line in lines:
+        new_line, changed = replace_relational_single_fline(f_line, cstyle)
+        new_lines.append(new_line)
+
+    return new_lines
 
 
 def replace_keywords_single_fline(f_line, case_dict):
@@ -1559,7 +1578,10 @@ def reformat_ffile_combined(infile, outfile, impose_indent=True, indent_size=3,
             f_line = f_line.strip(' ')
 
             if impose_replacements:
-                f_line = replace_relational_single_fline(f_line, cstyle)
+                f_line, relation_found = replace_relational_single_fline(f_line, cstyle)
+                if relation_found:
+                    updated_lines = replace_relational_lines(lines, cstyle)
+                    linebreak_pos = get_linebreak_pos(updated_lines, filter_fypp=not indent_fypp)
 
             if impose_case:
                 f_line = replace_keywords_single_fline(f_line, case_dict)
diff --git a/fprettify/tests/__init__.py b/fprettify/tests/__init__.py
index 5980930..6195cbb 100644
--- a/fprettify/tests/__init__.py
+++ b/fprettify/tests/__init__.py
@@ -381,7 +381,7 @@ def test_relation_replacement(self):
                     "'==== heading",
                     "if (vtk%my_rank .eq. 0) write (vtk%filehandle_par, '(\"<DataArray",
                     "'(\"</Collection>\",",
-                    "if (abc(1) .lt. -bca .or. &\n qwe .gt. ewq) then"]
+                    "if (abc(1)<=-bca .or. &\n qwe .gt. ewq) then"]
         f_outstring = ["if (min .lt. max .and. min .lt. thres)",
                      "if (min .gt. max .and. min .gt. thres)",
                      "if (min .eq. max .and. min .eq. thres)",
@@ -391,7 +391,7 @@ def test_relation_replacement(self):
                      "'==== heading",
                      "if (vtk%my_rank .eq. 0) write (vtk%filehandle_par, '(\"<DataArray",
                      "'(\"</Collection>\",",
-                     "if (abc(1) .lt. -bca .or. &\n    qwe .gt. ewq) then"]
+                     "if (abc(1) .le. -bca .or. &\n    qwe .gt. ewq) then"]
         c_outstring = ["if (min < max .and. min < thres)",
                      "if (min > max .and. min > thres)",
                      "if (min == max .and. min == thres)",
@@ -401,7 +401,7 @@ def test_relation_replacement(self):
                      "'==== heading",
                      "if (vtk%my_rank == 0) write (vtk%filehandle_par, '(\"<DataArray",
                       "'(\"</Collection>\",",
-                     "if (abc(1) < -bca .or. &\n    qwe > ewq) then"]
+                     "if (abc(1) <= -bca .or. &\n    qwe > ewq) then"]
         for i in range(0, len(instring)):
             self.assert_fprettify_result(['--enable-replacements', '--c-relations'], instring[i], c_outstring[i])
             self.assert_fprettify_result(['--enable-replacements'], instring[i], f_outstring[i])