diff --git a/backend/dmatrix.c b/backend/dmatrix.c
index 78df9398..a65ab761 100644
--- a/backend/dmatrix.c
+++ b/backend/dmatrix.c
@@ -1181,6 +1181,10 @@ int data_matrix_200(struct zint_symbol *symbol,const unsigned char source[], con
         while (matrixH[calcsize] != matrixW[calcsize]) {
             calcsize++;
         }
+        if (optionsize != -1) {
+            strcpy(symbol->errtxt, "Can not force square symbols when symbol size is selected");
+            error_number = ZINT_WARN_INVALID_OPTION;
+        }
     } else if (symbol->option_3 != DM_DMRE) {
         /* Skip DMRE symbols */
         while (isDMRE[calcsize]) {
diff --git a/docs/manual.txt b/docs/manual.txt
index ca885878..fbaf3b4c 100644
--- a/docs/manual.txt
+++ b/docs/manual.txt
@@ -1771,9 +1771,9 @@ Input  |  Symbol Size
 30     |  16 x 48
 ---------------------
 
-To force Zint only to use square symbols (versions 1-24) at the command line 
-use the option --square and when using the API set the value option_3 = 
-DM_SQUARE.
+When using automatic symbol sizes you can force Zint to use square symbols
+(versions 1-24) at the command line by using the option --square and when
+using the API by setting the value option_3 = DM_SQUARE.
 
 Data Matrix Rectangular Extension (DMRE) codes may be generated with the 
 following values as before:
diff --git a/frontend/main.c b/frontend/main.c
index 7697884b..9115995b 100644
--- a/frontend/main.c
+++ b/frontend/main.c
@@ -744,7 +744,11 @@ int main(int argc, char **argv) {
                         strcat(my_symbol->outfile, filetype);
                     }
                     error_number = escape_char_process(my_symbol, (unsigned char*) optarg, strlen(optarg));
-                    if (error_number == 0) {
+                    if (error_number < 5) {
+                        if (error_number != 0) {
+                            fprintf(stderr, "%s\n", my_symbol->errtxt);
+                            fflush(stderr);
+                        }
                         error_number = ZBarcode_Print(my_symbol, rotate_angle);
                     }
                     generated = 1;
@@ -763,7 +767,11 @@ int main(int argc, char **argv) {
             case 'i': /* Take data from file */
                 if (batch_mode == 0) {
                     error_number = ZBarcode_Encode_File(my_symbol, optarg);
-                    if (error_number == 0) {
+                    if (error_number < 5) {
+                        if (error_number != 0) {
+                            fprintf(stderr, "%s\n", my_symbol->errtxt);
+                            fflush(stderr);
+                        }
                         error_number = ZBarcode_Print(my_symbol, rotate_angle);
                     }
                     generated = 1;