diff --git a/src/HMMer2/prior.c b/src/HMMer2/prior.c
index a40eb9c..bbec7bf 100644
--- a/src/HMMer2/prior.c
+++ b/src/HMMer2/prior.c
@@ -8,6 +8,7 @@
 #include "structs.h"
 #include "funcs.h" 
 #include "squid.h"
+#include <string.h>
 
 #ifdef MEMDEBUG
 #include "dbmalloc.h"
diff --git a/src/makefile b/src/makefile
index 7fd404a..4fbb930 100644
--- a/src/makefile
+++ b/src/makefile
@@ -22,7 +22,7 @@
 # Change the cc line to gcc if you get compiler errors
 # Most likely you have a non ANSI C compiler
 # CC =  /opt/intel_cc_80/bin/icc
-CC = cc
+CC ?= cc
 
 # These are the CFLAGS to use. These days Wise2 is inherently
 # pthreaded, and everything is compiled with threads. However
diff --git a/src/dnaindex/compressed_protein_index.c b/src/dnaindex/compressed_protein_index.c
index 00720b5..85227d0 100644
--- a/src/dnaindex/compressed_protein_index.c
+++ b/src/dnaindex/compressed_protein_index.c
@@ -199,7 +199,7 @@ boolean add_direct_number_CompressedProteinIndex(void * data,int seq_number,Sequ
 {
   fatal("For compressed protein indexes, impossible to add numbers directly");
 
-  return NULL;
+  return FALSE;
 }
 
 # line 226 "compressed_protein_index.dy"
diff --git a/src/models/motifmatrix.c b/src/models/motifmatrix.c
index 8c6a8aa..bfb2270 100644
--- a/src/models/motifmatrix.c
+++ b/src/models/motifmatrix.c
@@ -407,7 +407,7 @@ MotifConsMatrix * MotifConsMatrix_alloc_matrix(int leni,int lenj)
 
     for(i=0;i<leni;i++)  {  
       for(j=0;j<lenj;j++)    
-        out->mat[i][j] = NULL;   
+        out->mat[i][j] = '0';   
       }  
 
 