diff --git a/getcoeff.c b/getcoeff.c
index 02abbbe..e02a3ca 100644
--- a/getcoeff.c
+++ b/getcoeff.c
@@ -936,8 +936,9 @@ init_coeffs( void ) {
   getcwd(sPatternFile, sizeof(sPatternFile));
   strcat(sPatternFile, "/" PATTERN_FILE);
 #endif
+  char* env_coeffs = getenv("COEFFS_PATH");
 
-  coeff_stream = gzopen( sPatternFile, "rb" );
+  coeff_stream = gzopen(env_coeffs ? env_coeffs : sPatternFile, "rb" );
   if ( coeff_stream == NULL )
     fatal_error( "%s '%s'\n", FILE_ERROR, sPatternFile );
 
diff --git a/zebra.c b/zebra.c
index 6ade0e8..a8e11fd 100644
--- a/zebra.c
+++ b/zebra.c
@@ -609,8 +609,13 @@ main( int argc, char *argv[] ) {
   global_setup( use_random, hash_bits );
   init_thor_database();
 
-  if ( use_book )
-    init_learn( "book.bin", TRUE );
+  if ( use_book ) {
+      char *book_filename = getenv("BOOK_PATH");
+      if (book_filename == NULL) {
+          book_filename = "book.bin";
+      }
+      init_learn(book_filename, TRUE );
+  }
   if ( use_random && !SCRIPT_ONLY ) {
     time( &timer );
     my_srandom( timer );