diff --git a/patterns/dfa.c b/patterns/dfa.c
index 3689616..2d2f8c6 100644
--- a/patterns/dfa.c
+++ b/patterns/dfa.c
@@ -279,7 +279,7 @@ resize_dfa(dfa_t *pdfa, int max_states, int max_indexes)
  * dump a dfa (debugging purpose).
  */
 
-static const char *line =
+static const char line[] =
   "----------------------------------------------------\n";
 
 void
diff --git a/patterns/mkpat.c b/patterns/mkpat.c
index 70a6964..5f1f1dd 100644
--- a/patterns/mkpat.c
+++ b/patterns/mkpat.c
@@ -1419,7 +1419,7 @@ generate_autohelper_code(int funcno, int number_of_params, int *labels)
     /* A common case. Just use the labels as parameters. */
     switch (number_of_params) {
     case 0:
-      code_pos += sprintf(code_pos, autohelper_functions[funcno].code);
+      code_pos += sprintf(code_pos, "%s", autohelper_functions[funcno].code);
       break;
     case 1:
       code_pos += sprintf(code_pos, autohelper_functions[funcno].code,
diff --git a/patterns/uncompress_fuseki.c b/patterns/uncompress_fuseki.c
index 3290b05..c67a733 100644
--- a/patterns/uncompress_fuseki.c
+++ b/patterns/uncompress_fuseki.c
@@ -224,9 +224,9 @@ main(int argc, char *argv[])
 
   assert(boardsize > 0);
   if (boardsize > MAX_BOARD) {
-    printf(output_strings[PREAMBLE]);
+    printf("%s", output_strings[PREAMBLE]);
     printf(output_strings[HEADER], boardsize);
-    printf(output_strings[FOOTER]);
+    printf("%s", output_strings[FOOTER]);
     return EXIT_SUCCESS;
   }
   
@@ -251,7 +251,7 @@ main(int argc, char *argv[])
     board[k][boardsize + 1] = '|';
   }
 
-  printf(output_strings[PREAMBLE]);
+  printf("%s", output_strings[PREAMBLE]);
   printf(output_strings[HEADER], boardsize);
   
 
@@ -308,7 +308,7 @@ main(int argc, char *argv[])
   if (mode == C_OUTPUT)
     write_pattern_c_code(NULL, board1d, NO_MOVE, 0, boardsize, -1);
   
-  printf(output_strings[FOOTER]);
+  printf("%s", output_strings[FOOTER]);
 
   return EXIT_SUCCESS;
 }