diff --git a/logv2.c b/logv2.c
index 9528f214..d418e148 100644
--- a/logv2.c
+++ b/logv2.c
@@ -221,7 +221,7 @@ int subsystemFromText(const char *text)
       return i;
     }
   }
-  return -1;
+  return SINVALID;
 } 
 /*----------------------------------------------------------------------------*/
 void formatSubsystem(unsigned int sub, char *buffer, unsigned int bufferLength)
@@ -265,7 +265,7 @@ unsigned int logFilter(unsigned int severity, const char *subsystem, const char
     If it is in the list of enabled subsystems, everything is logged
   */
   sub = subsystemFromText(subsystem);
-  if(sub >= 0 && severity <= logEnabledArray[sub]){
+  if((sub >= 0 && sub <= SINVALID) && severity <= logEnabledArray[sub]){
     return 0;
   }
 
diff --git a/logv2.h b/logv2.h
index 07a84f10..30485da1 100644
--- a/logv2.h
+++ b/logv2.h
@@ -38,7 +38,7 @@
 #define SHISTORY 7
 #define SINVALID 8
 
-#define MAXSUB 7
+#define MAXSUB 8
  
 
 /* write a log message