diff --git a/src/oclHashcat.c b/src/oclHashcat.c
index 0469d4ec9..70fcf6a3f 100644
--- a/src/oclHashcat.c
+++ b/src/oclHashcat.c
@@ -12300,7 +12300,12 @@ int main (int argc, char **argv)
       return (-1);
     }
 
-    uint CL_platform_sel = 0;
+    uint CL_platform_sel = 1;
+
+    if (opencl_platform != NULL)
+    {
+      CL_platform_sel = atoi (opencl_platform);
+    }
 
     if (CL_platforms_cnt > 1)
     {
@@ -12330,7 +12335,12 @@ int main (int argc, char **argv)
       }
       else
       {
-        CL_platform_sel = atoi (opencl_platform);
+        if (CL_platform_sel < 1)
+        {
+          log_error ("ERROR: --opencl-platform < 1");
+
+          return (-1);
+        }
 
         if (CL_platform_sel > CL_platforms_cnt)
         {
@@ -12338,13 +12348,23 @@ int main (int argc, char **argv)
 
           return (-1);
         }
+      }
+    }
+    else
+    {
+      if (CL_platform_sel != 1)
+      {
+        log_error ("ERROR: OpenCL platform number %d is not available", CL_platform_sel);
 
-        // user does not count with zero
-
-        CL_platform_sel -= 1;
+        return (-1);
       }
     }
 
+    // zero-indexed: not starting to count at 1, as user does
+
+    CL_platform_sel -= 1;
+
+
     cl_platform_id CL_platform = CL_platforms[CL_platform_sel];
 
     char CL_platform_vendor[INFOSZ];