diff --git a/apps/encoder.c b/apps/encoder.c
index 0bad34878bedc00a8d67d921b9a953db0af9531f..005794d939b2fd41279963342142bdaa2c366d31 100644
--- a/apps/encoder.c
+++ b/apps/encoder.c
@@ -1273,8 +1273,21 @@ static bool parseCmdlIVAS_enc(
             arg->inputFormat = IVAS_ENC_INPUT_ISM;
             i++;
 
+#ifdef IMPROVE_CMDLINE_ROBUSTNESS
+            if ( i < argc - 4 )
+#else
             if ( i < argc - 5 )
+#endif
             {
+#ifdef IMPROVE_CMDLINE_ROBUSTNESS
+                if ( !is_digits_only( argv[i] ) )
+                {
+                    fprintf( stderr, "Error: Number of ISM channels must be an integer number!\n\n" );
+                    usage_enc();
+                    return false;
+                }
+#endif
+
                 if ( sscanf( argv[i], "%d", &tmp ) > 0 )
                 {
                     i++;
@@ -1286,6 +1299,14 @@ static bool parseCmdlIVAS_enc(
                     usage_enc();
                     return false;
                 }
+#ifdef IMPROVE_CMDLINE_ROBUSTNESS
+                else if ( tmp > IVAS_MAX_NUM_OBJECTS )
+                {
+                    fprintf( stderr, "Error: Too high number of ISM channels specified!\n\n" );
+                    usage_enc();
+                    return false;
+                }
+#endif
                 else
                 {
                     arg->inputFormatConfig.ism.numObjects = (int16_t) tmp;
@@ -1317,7 +1338,11 @@ static bool parseCmdlIVAS_enc(
                 }
                 else
                 {
+#ifdef IMPROVE_CMDLINE_ROBUSTNESS
+                    fprintf( stderr, "Error: not enough metadata arguments specified!\n\n" );
+#else
                     fprintf( stderr, "Error: not enough arguments\n\n" );
+#endif
                     usage_enc();
                     return false;
                 }
@@ -1329,17 +1354,25 @@ static bool parseCmdlIVAS_enc(
             arg->inputFormat = IVAS_ENC_INPUT_SBA;
 
             /* SBA configuration */
-            if ( i < argc - 4 )
+            if ( i < argc - 4
+#ifdef IMPROVE_CMDLINE_ROBUSTNESS
+                 && is_number( argv[i] ) && sscanf( argv[i], "%d", &tmp ) > 0
+#endif
+            )
             {
+#ifndef IMPROVE_CMDLINE_ROBUSTNESS
                 if ( sscanf( argv[i], "%d", &tmp ) > 0 )
                 {
+#endif
                     i++;
+#ifndef IMPROVE_CMDLINE_ROBUSTNESS
                 }
+#endif
             }
             else
             {
                 tmp = -1; /* this is to avoid a compilation warning */
-                fprintf( stderr, "Error: SBA order not specified!\n\n" );
+                fprintf( stderr, "Error: SBA order must be specified, expecting a number!\n\n" );
                 usage_enc();
                 return false;
             }
@@ -1371,6 +1404,15 @@ static bool parseCmdlIVAS_enc(
 
             if ( i < argc - 4 )
             {
+#ifdef IMPROVE_CMDLINE_ROBUSTNESS
+                if ( !is_digits_only( argv[i] ) )
+                {
+                    fprintf( stderr, "Error: Number of MASA channels must be an integer number!\n\n" );
+                    usage_enc();
+                    return false;
+                }
+#endif
+
                 if ( sscanf( argv[i], "%d", &tmp ) > 0 )
                 {
                     i++;
@@ -1385,7 +1427,11 @@ static bool parseCmdlIVAS_enc(
                         arg->inputFormatConfig.masaVariant = IVAS_ENC_MASA_2CH;
                         break;
                     default:
+#ifdef IMPROVE_CMDLINE_ROBUSTNESS
+                        fprintf( stderr, "Error: MASA channels must be 1 or 2.\n\n" );
+#else
                         fprintf( stderr, "Error: MASA channels must for the moment be 1 or 2.\n\n" );
+#endif
                         usage_enc();
                         return false;
                 }
@@ -1410,7 +1456,6 @@ static bool parseCmdlIVAS_enc(
 
             if ( i < argc - 4 )
             {
-
                 if ( strcmp( to_upper( argv[i] ), "5_1" ) == 0 )
                 {
                     arg->inputFormatConfig.mcLayout = IVAS_ENC_MC_5_1;
diff --git a/lib_com/options.h b/lib_com/options.h
index 9dc8ab44c80be8e4f09041ddd95648f28ab549dc..8a84da5d9f5375155690d2e4d2f53caa446133d5 100644
--- a/lib_com/options.h
+++ b/lib_com/options.h
@@ -153,7 +153,7 @@
 #define FIX_ITD_CNG                                     /* Eri Contribution 11: Fix for CNG ITD */
 #define FIX_VBR_COMPLEXITY                              /* Issue 234: fix extremely high complexity numbers for IVAS EVS mode */
 #define FIX_ISM_INACTIVE_BITS                           /* Issue 230: fix bitbudget distribution in inactive frames in ISM format */
-
+#define IMPROVE_CMDLINE_ROBUSTNESS                      /* Issue 233: Improve robustness of command-line parameters */
 
 
 /* ################## End DEVELOPMENT switches ######################### */
diff --git a/lib_util/cmdl_tools.c b/lib_util/cmdl_tools.c
index d0d2d0d374eec0328fa6aeb56df3024f28880921..d36112f8a305716af771731437523d206d54fe7d 100644
--- a/lib_util/cmdl_tools.c
+++ b/lib_util/cmdl_tools.c
@@ -62,7 +62,7 @@ char *to_upper( char *str )
  * Check if a string contains only digits.
  *---------------------------------------------------------------------*/
 
-bool is_digits_only( char *str )
+bool is_digits_only( const char *str )
 {
     int16_t i;
 
@@ -86,19 +86,58 @@ bool is_digits_only( char *str )
  * Check if a string is a number.
  *---------------------------------------------------------------------*/
 
-bool is_number( char *str )
+bool is_number( const char *str )
 {
+    bool decimal_separator_found;
     int16_t i;
+    int16_t numeric_len;
 
+    decimal_separator_found = false;
     i = 0;
+    numeric_len = 0;
+
+    /* Check for null string or sign character */
+    if ( str[i] == '\0' )
+    {
+        return false;
+    }
+    else if ( str[i] == '+' || str[i] == '-' )
+    {
+        i++;
+    }
+
+    /* Ensure rest of string is numeric and only one decimal separator is present */
     while ( str[i] != 0 )
     {
-        if ( ( str[i] < '0' || str[i] > '9' ) && str[i] != '.' && str[i] != '-' && str[i] != '\n' && str[i] != '\r' )
+        if ( str[i] < '0' || str[i] > '9' )
         {
-            return false;
+            if ( str[i] == '.' )
+            {
+                if ( decimal_separator_found )
+                {
+                    return false;
+                }
+                else
+                {
+                    decimal_separator_found = true;
+                }
+            }
+            else if ( str[i] != '\r' && str[i] != '\n' )
+            {
+                return false;
+            }
+        }
+        else
+        {
+            numeric_len++;
         }
         i++;
     }
 
+    if ( numeric_len == 0 )
+    {
+        return false;
+    }
+
     return true;
 }
diff --git a/lib_util/cmdl_tools.h b/lib_util/cmdl_tools.h
index 829ec985b0314f375f3489447296734754423617..52b6e694536c376bea5bff1160d98ecaa09d8ce4 100644
--- a/lib_util/cmdl_tools.h
+++ b/lib_util/cmdl_tools.h
@@ -36,9 +36,9 @@
 #include <stdbool.h>
 #include <stdint.h>
 
-bool is_digits_only( char *str );
+bool is_digits_only( const char *str );
 
-bool is_number( char *str );
+bool is_number( const char *str );
 
 char *to_upper( char *str );