diff --git a/tools/firmware-utils/Makefile b/tools/firmware-utils/Makefile
index 69cba69a58..337d63582e 100644
--- a/tools/firmware-utils/Makefile
+++ b/tools/firmware-utils/Makefile
@@ -73,7 +73,7 @@ define Host/Compile
 	$(call cc,mkdcs932, -Wall)
 	$(call cc,mkheader_gemtek,-lz)
 	$(call cc,mkrtn56uimg, -lz)
-	$(call cc,dgn3500sum)
+	$(call cc,dgn3500sum, -Wall)
 	$(call cc,edimax_fw_header, -Wall)
 	$(call cc,mkmerakifw sha1, -Wall)
 	$(call cc,mkmerakifw-old, -Wall)
diff --git a/tools/firmware-utils/src/dgn3500sum.c b/tools/firmware-utils/src/dgn3500sum.c
index 00a0c5f837..eb80e6c01b 100644
--- a/tools/firmware-utils/src/dgn3500sum.c
+++ b/tools/firmware-utils/src/dgn3500sum.c
@@ -103,7 +103,7 @@ int main(int argc, char** argv)
   unsigned long start, i;
   char *endptr, *buffer, *p;
   int count;  // size of file in bytes
-  unsigned short sum, sum1;
+  unsigned short sum = 0, sum1 = 0;
   char sumbuf[9];
 
   if(argc < 3) {
@@ -117,7 +117,7 @@ int main(int argc, char** argv)
     printf("ERROR: File not writeable!\n");
     return 1;
   }
-  if(argc = 4)
+  if(argc == 4)
   {
     printf("%s: PID type: %s\n", argv[0], argv[3]);
     if(strcmp(argv[3], "DE")==0)
@@ -147,7 +147,6 @@ int main(int argc, char** argv)
 
   start = strtol(argv[2], &endptr, 16);
   p = buffer+start;
-  sum1 = 0;
   for(i = 0; i < count - start; i++)
   {
 	sum1 += p[i];