diff --git a/src/util/argv.c b/src/util/argv.c
index 54d4e8b814..b578d6777f 100644
--- a/src/util/argv.c
+++ b/src/util/argv.c
@@ -20,7 +20,7 @@ int ompi_argv_append(int *argc, char ***argv, const char *arg)
   /* Create new argv. */
 
   if (NULL == *argv) {
-    *argv = malloc(2 * sizeof(char *));
+      *argv = (char**) malloc(2 * sizeof(char *));
     if (NULL == *argv)
       return OMPI_ERROR;
     *argc = 0;
@@ -31,14 +31,14 @@ int ompi_argv_append(int *argc, char ***argv, const char *arg)
   /* Extend existing argv. */
 
   else {
-    *argv = realloc(*argv, (*argc + 2) * sizeof(char *));
+      *argv = (char**) realloc(*argv, (*argc + 2) * sizeof(char *));
     if (NULL == *argv)
       return OMPI_ERROR;
   }
 
   /* Set the newest element to point to a copy of the arg string */
 
-  (*argv)[*argc] = malloc(strlen(arg) + 1);
+  (*argv)[*argc] = (char*) malloc(strlen(arg) + 1);
   if (NULL == (*argv)[*argc])
     return OMPI_ERROR;
 
@@ -105,7 +105,7 @@ char **ompi_argv_split(const char *src_string, int delimiter)
     /* long argument, malloc buffer, copy and add */
 
     else if (arglen > (ARGSIZE - 1)) {
-      argtemp = malloc(arglen + 1);
+        argtemp = (char*) malloc(arglen + 1);
       if (NULL == argtemp)
 	return NULL;
 
@@ -178,7 +178,7 @@ char *ompi_argv_join(char **argv, int delimiter)
 
   /* Allocate the string. */
 
-  if (NULL == (str = malloc(str_len)))
+  if (NULL == (str = (char*) malloc(str_len)))
     return NULL;
 
   /* Loop filling in the string. */
@@ -326,8 +326,8 @@ int ompi_argv_insert(char ***target, int start, char **source)
 
         /* Alloc out new space */
 
-        *target = realloc(*target, 
-                          sizeof(char *) * (target_count + source_count + 1));
+        *target = (char**) realloc(*target, 
+                                   sizeof(char *) * (target_count + source_count + 1));
 
         /* Move suffix items down to the end */
 
diff --git a/src/util/bufpack.c b/src/util/bufpack.c
index 19cc5bc864..195b1692d3 100644
--- a/src/util/bufpack.c
+++ b/src/util/bufpack.c
@@ -352,7 +352,8 @@ return (OMPI_SUCCESS);
  */
     int ompi_pack(ompi_buffer_t buffer, void * src, size_t n, ompi_pack_type_t type)
 {
-    int i, rc;
+    int rc;
+    size_t i;
     void *dest;
     ompi_buffer_internal_t* bptr;
     size_t op_size=0;
@@ -439,7 +440,7 @@ return (OMPI_SUCCESS);
             }
             break;
         case OMPI_STRING:
-            strncpy(dest, src, n);
+            strncpy((char*) dest, (char*) src, n);
             *((char *) dest + n - 1) = '\0';
             break;
         case OMPI_NAME:
@@ -478,9 +479,10 @@ return (OMPI_SUCCESS);
  * @retval OMPI_SUCCESS
  * @retval OMPI_ERROR
  */ 
-    int ompi_unpack(ompi_buffer_t buffer, void * dest, size_t n, ompi_pack_type_t type)
+int
+ompi_unpack(ompi_buffer_t buffer, void * dest, size_t n, ompi_pack_type_t type)
 {
-    int i;
+    size_t i;
     void *src;
     ompi_buffer_internal_t* bptr;
     size_t op_size=0;
@@ -555,7 +557,7 @@ return (OMPI_SUCCESS);
             }
             break;
         case OMPI_STRING:
-            strncpy(dest, src, n);
+            strncpy((char*) dest, (char*) src, n);
             *((char *) dest + n - 1) = '\0';
             break;
         case OMPI_NAME:
diff --git a/src/util/cmd_line.c b/src/util/cmd_line.c
index a464793dd7..78e0e2b9a3 100644
--- a/src/util/cmd_line.c
+++ b/src/util/cmd_line.c
@@ -423,7 +423,7 @@ char *ompi_cmd_line_get_usage_msg(ompi_cmd_line_t *cmd)
                 if (NULL != line) {
                     free(line);
                 }
-                line = malloc(len * 2);
+                line = (char*) malloc(len * 2);
                 if (NULL == line) {
                     ompi_mutex_unlock(&cmd->lcl_mutex);
                     return NULL;
diff --git a/src/util/if.c b/src/util/if.c
index d7a63aba8e..1cc8a6d689 100644
--- a/src/util/if.c
+++ b/src/util/if.c
@@ -135,7 +135,7 @@ static int ompi_ifinit(void)
         }
         memcpy(&intf.if_mask, &ifr->ifr_addr, sizeof(intf.if_mask));
 
-        intf_ptr = malloc(sizeof(ompi_if_t));
+        intf_ptr = (ompi_if_t*) malloc(sizeof(ompi_if_t));
         if(intf_ptr == 0) {
             ompi_output(0, "ompi_ifinit: unable to allocated %d bytes\n", sizeof(ompi_if_t));
             return OMPI_ERR_OUT_OF_RESOURCE;
diff --git a/src/util/numtostr.c b/src/util/numtostr.c
index 1107b854e6..0bb43978ae 100644
--- a/src/util/numtostr.c
+++ b/src/util/numtostr.c
@@ -17,7 +17,7 @@ ompi_ltostr(long num)
     char *buf = NULL;
     int ret = 0;
 
-    buf = malloc(sizeof(char) * buflen);
+    buf = (char*) malloc(sizeof(char) * buflen);
     if (NULL == buf) return NULL;
     
     ret = snprintf(buf, buflen, "%ld", num);
@@ -38,7 +38,7 @@ ompi_dtostr(double num)
     char *buf = NULL;
     int ret = 0;
     
-    buf = malloc(sizeof(char) * buflen);
+    buf = (char*) malloc(sizeof(char) * buflen);
     if (NULL == buf) return NULL;
     
     ret = snprintf(buf, buflen, "%f", num);
diff --git a/src/util/output.c b/src/util/output.c
index 4628c1671c..9817bad702 100644
--- a/src/util/output.c
+++ b/src/util/output.c
@@ -401,7 +401,7 @@ static int open_file(int i)
 
     dir = ompi_process_info.proc_session_dir;
     if (NULL != dir) {
-        filename = malloc(MAXPATHLEN);
+        filename = (char*) malloc(MAXPATHLEN);
         if (NULL == filename) {
             return OMPI_ERR_OUT_OF_RESOURCE;
         }
@@ -519,7 +519,7 @@ static void output(int output_id, char *format, va_list arglist)
       if (NULL != temp_str) {
 	free(temp_str);
       }
-      temp_str = malloc(total_len * 2);
+      temp_str = (char*) malloc(total_len * 2);
       temp_str_len = total_len * 2;
     }
     if (NULL != ldi->ldi_prefix) {
diff --git a/src/util/path.c b/src/util/path.c
index 90c141e465..4641be469d 100644
--- a/src/util/path.c
+++ b/src/util/path.c
@@ -82,7 +82,7 @@ ompi_path_findv(char *fname, char **pathv, int mode, char **envv)
                 if (!delimit) {
                     fullpath = path_access(fname, env, mode);
                 } else {
-                    pfix = malloc(strlen(env) + strlen(delimit) + 1);
+                    pfix = (char*) malloc(strlen(env) + strlen(delimit) + 1);
                     if (NULL == pfix){
                         return(0);
                     }
@@ -224,7 +224,7 @@ path_access(char *fname, char *path, int mode)
     /*
      * Allocate space for the full pathname.
      */
-    fullpath = malloc(strlen(path) + strlen(fname) + 2);
+    fullpath = (char*) malloc(strlen(path) + strlen(fname) + 2);
     if (NULL == fullpath){
         return(0);
     }
diff --git a/src/util/printf.c b/src/util/printf.c
index cc0d94790f..de8adec6d3 100644
--- a/src/util/printf.c
+++ b/src/util/printf.c
@@ -27,7 +27,7 @@ static int guess_strlen(const char *fmt, va_list ap)
     char *sarg;
     double darg;
     float farg;
-    int i;
+    size_t i;
     int iarg;
     int len;
     long larg;
@@ -192,7 +192,7 @@ int ompi_vasprintf(char **ptr, const char *fmt, va_list ap)
     length = vsprintf(*ptr, fmt, ap);
 
     /* realloc */
-    *ptr = realloc(*ptr, (size_t) length + 1);
+    *ptr = (char*) realloc(*ptr, (size_t) length + 1);
     if (NULL == *ptr) {
         errno = ENOMEM;
         return -1;
diff --git a/src/util/show_help.c b/src/util/show_help.c
index a4223d0746..7a319cf456 100644
--- a/src/util/show_help.c
+++ b/src/util/show_help.c
@@ -240,7 +240,7 @@ static int output(bool want_error_header, ompi_pointer_array_t *lines,
 
     len = want_error_header ? 2 * strlen(star_line) : 0;
     for (i = 0; i < ompi_pointer_array_get_size(lines); ++i) {
-        tmp = ompi_pointer_array_get_item(lines, i);
+        tmp = (char*) ompi_pointer_array_get_item(lines, i);
         if (NULL == tmp) {
             break;
         }
@@ -249,7 +249,7 @@ static int output(bool want_error_header, ompi_pointer_array_t *lines,
 
     /* Malloc it out */
 
-    concat = malloc(len + 1);
+    concat = (char*) malloc(len + 1);
     if (NULL == concat) {
         fprintf(stderr, star_line);
         fprintf(stderr, "Sorry!  You were supposed to get help about:\n    %s\nfrom the file:\n    %s\n", topic, base);
@@ -265,7 +265,7 @@ static int output(bool want_error_header, ompi_pointer_array_t *lines,
         strcat(concat, star_line);
     }
     for (i = 0; i < ompi_pointer_array_get_size(lines); ++i) {
-        tmp = ompi_pointer_array_get_item(lines, i);
+        tmp = (char*) ompi_pointer_array_get_item(lines, i);
         if (NULL == tmp) {
             break;
         }
@@ -301,7 +301,7 @@ static int destroy_message(ompi_pointer_array_t *lines)
     char *tmp;
 
     for (i = 0; i < ompi_pointer_array_get_size(lines); ++i) {
-        tmp = ompi_pointer_array_get_item(lines, i);
+        tmp = (char*) ompi_pointer_array_get_item(lines, i);
         if (NULL == tmp) {
             break;
         }
diff --git a/src/util/show_help_lex.l b/src/util/show_help_lex.l
index fd55d14513..4e5beb6200 100644
--- a/src/util/show_help_lex.l
+++ b/src/util/show_help_lex.l
@@ -16,7 +16,13 @@ int ompi_show_help_finish_parsing(void);
 /*
  * local functions
  */
-static int ompi_show_help_yywrap(void);
+#ifdef __cplusplus
+ extern "C" {
+#endif
+     static int ompi_show_help_yywrap(void);
+#ifdef __cplusplus
+ }
+#endif
 
 /*
  * global variables
diff --git a/src/util/strncpy.c b/src/util/strncpy.c
index 8b48b33ba2..c2289ee3b9 100644
--- a/src/util/strncpy.c
+++ b/src/util/strncpy.c
@@ -31,7 +31,7 @@
 char *
 ompi_strncpy(char *dest, const char *src, size_t len)
 {
-  int i;
+  size_t i;
   int pad = 0;
   char *new_dest = dest;