diff --git a/src/slarray.c b/src/slarray.c

index d26aaec..6c338b5 100644

--- a/src/slarray.c

+++ b/src/slarray.c

@@ -22,6 +22,7 @@ USA.

 #include "slinclud.h"

 #include <math.h>

+#include <limits.h>

 /* #define SL_APP_WANTS_FOREACH */

 #include "slang.h"

@@ -312,6 +313,26 @@ void SLang_free_array (SLang_Array_Type *at)

    free_array (at);

 }

+/* Here, a and b are assumed to be non-negative */

+static int check_overflow_mult_i (SLindex_Type a, SLindex_Type b, SLindex_Type *cp)

+{

+   if ((a < 0) || (b < 0) || ((b > 0) && (a > INT_MAX/b)))

+     return -1;

+

+   *cp = a*b;

+

+   return 0;

+}

+

+static int check_overflow_mult_ui (SLuindex_Type a, SLindex_Type b, SLuindex_Type *cp)

+{

+   if ((b < 0) || ((b > 0) && (a > UINT_MAX/(SLuindex_Type)b)))

+     return -1;

+

+   *cp = a*(SLuindex_Type)b;

+   return 0;

+}

+

 SLang_Array_Type *

 SLang_create_array1 (SLtype type, int read_only, VOID_STAR data,

 		     SLindex_Type *dims, unsigned int num_dims, int no_init)

@@ -366,16 +387,14 @@ SLang_create_array1 (SLtype type, int read_only, VOID_STAR data,

    num_elements = 1;

    for (i = 0; i < num_dims; i++)

      {

-	SLindex_Type new_num_elements;

 	at->dims[i] = dims[i];

-	new_num_elements = dims[i] * num_elements;

-	if (dims[i] && (new_num_elements/dims[i] != num_elements))

+

+	if (-1 == check_overflow_mult_i (num_elements, dims[i], &num_elements))

 	  {

 	     throw_size_error (SL_Index_Error);

 	     free_array (at);

 	     return NULL;

 	  }

-	num_elements = new_num_elements;

      }

    /* Now set the rest of the unused dimensions to 1.  This makes it easier

@@ -395,8 +414,10 @@ SLang_create_array1 (SLtype type, int read_only, VOID_STAR data,

 	return at;

      }

-   size = (num_elements * sizeof_type);

-   if ((size/sizeof_type != num_elements) || (size < 0))

+   /* SLmalloc is currently limited to the use of unsigned integers.

+    * So include the size of the type as well.

+    */

+   if (-1 == check_overflow_mult_i (num_elements, sizeof_type, &size))

      {

 	throw_size_error (SL_INVALID_PARM);

 	free_array (at);

@@ -1103,7 +1124,6 @@ convert_nasty_index_objs (SLang_Array_Type *at,

    total_num_elements = 1;

    for (i = 0; i < num_indices; i++)

      {

-	SLuindex_Type new_total_num_elements;

 	SLang_Object_Type *obj = index_objs + i;

 	range_delta_buf [i] = 0;

@@ -1145,13 +1165,11 @@ convert_nasty_index_objs (SLang_Array_Type *at,

 	       }

 	  }

-	new_total_num_elements = total_num_elements * max_dims[i];

-	if (max_dims[i] && (new_total_num_elements/max_dims[i] != total_num_elements))

+	if (-1 == check_overflow_mult_ui (total_num_elements, max_dims[i], &total_num_elements))

 	  {

 	     throw_size_error (SL_INVALID_PARM);

 	     return -1;

 	  }

-       total_num_elements = new_total_num_elements;

      }

    *num_elements = total_num_elements;