--- a/src/kurtz/libbasedir/space.c
+++ b/src/kurtz/libbasedir/space.c
@@ -379,7 +379,7 @@
   }
   if(numberofblocks > 0)
   {
-    fprintf(stderr,"space leak: number of blocks = %u\n",numberofblocks);
+    fprintf(stderr,"space leak: number of blocks = %lu\n",numberofblocks);
     exit(EXIT_FAILURE);
   } 
   free(blocks);
--- a/src/tigr/combineMUMs.cc
+++ b/src/tigr/combineMUMs.cc
@@ -106,7 +106,7 @@
     //  This array [i]  is the maximum number of errors allowed
     //  in a match between sequences of length  i , which is
     //  i * MAXERROR_RATE .
-char  * Error_File_Name = DEFAULT_ERROR_FILE_NAME;
+const char  * Error_File_Name = DEFAULT_ERROR_FILE_NAME;
     // Name of file to write gaps listing with # errors in each gap
 int  Fill_Ct = 0;
     // Number of non-acgt bases in ref sequence
@@ -132,7 +132,7 @@
     // The query sequence
 long int  Query_Len;
     // The length of the query sequence
-char  * Query_Suffix = "Query";
+const char  * Query_Suffix = "Query";
     // Suffix for query tag
 char  * Ref = NULL;
     // The reference sequence
@@ -142,7 +142,7 @@
     // The length of the reference sequence
 long int  Ref_Size;
     // The size of the reference sequence buffer
-char  * Ref_Suffix = "Ref";
+const char  * Ref_Suffix = "Ref";
     // Suffix for reference tag
 int  Show_Differences = FALSE;
     // If  TRUE  then show differences in all alignments
--- a/src/tigr/mgaps.cc
+++ b/src/tigr/mgaps.cc
@@ -64,9 +64,9 @@
 static void  Parse_Command_Line
     (int argc, char * argv []);
 static void  Process_Matches
-    (Match_t * A, int N, char * label);
+    (Match_t * A, int N, const char * label);
 static int  Process_Cluster
-    (Match_t * A, int N, char * label);
+    (Match_t * A, int N, const char * label);
 static void  Union
     (int a, int b);
 static void  Usage
@@ -438,7 +438,7 @@
 
 
 static int  Process_Cluster
-    (Match_t * A, int N, char * label)
+    (Match_t * A, int N, const char * label)
 
 //  Process the cluster of matches in  A [0 .. (N - 1)]  and output them
 //  after a line containing  label .  Return the number of clusters
@@ -552,7 +552,7 @@
 
 
 static void  Process_Matches
-    (Match_t * A, int N, char * label)
+    (Match_t * A, int N, const char * label)
 
 //  Process matches  A [1 .. N]  and output them after
 //  a line containing  label .
--- a/src/tigr/show-coords.cc
+++ b/src/tigr/show-coords.cc
@@ -788,7 +788,7 @@
      (vector<AlignStats> Stats)
 {
   time_t currtime;
-  char * type;
+  const char * type;
   char date[MAX_LINE];
   long int len;
   vector<AlignStats>::iterator Sip;