diff --git a/src/lti_input_idx.cc b/src/lti_input_idx.cc
index 76680ba0..1882b9bf 100644
--- a/src/lti_input_idx.cc
+++ b/src/lti_input_idx.cc
@@ -93,8 +93,13 @@ Read the source code in @code{lti_input_idx.cc} for details.\n\
       offset = 1;
     }
 
+#if OCTAVE_MAJOR_VERSION > 8
     octave::range<double> mat_idx (1, idx-offset);
     octave::range<double> opt_idx (idx+1-offset, len);
+#else
+    Range mat_idx (1, idx-offset);
+    Range opt_idx (idx+1-offset, len);
+#endif
 
     retval(2) = offset;     // abused as logical in the LTI constructors
     retval(1) = opt_idx;
diff --git a/src/sl_ab08nd.cc b/src/sl_ab08nd.cc
index 54c8b902..371eb716 100644
--- a/src/sl_ab08nd.cc
+++ b/src/sl_ab08nd.cc
@@ -198,7 +198,11 @@ For internal use only.")
         if (m == 1 && p == 1)
         {
             if (nu < n)
+#if OCTAVE_MAJOR_VERSION > 8
                 gain = c * octave::xpow (a, double (n-1-nu)).matrix_value() * b;
+#else
+                gain = c * xpow (a, double (n-1-nu)).matrix_value() * b;
+#endif
             else
                 gain = d;
         }